ENH Support SDL-based packages and add pyxel. ### Description

This adds SDL-based package support to Pyodide and adds pyxel as a PoC. Most of the troubleshooting is done by @kitao and pyxel devs, a big thanks to them.

This is on top of #3505

1) I linked only js part of SDL libraries to the main module and linked the native parts to the side module. So the size increase of the main module is small enough (~0.1MB increase to the pyodide.asm.js).

Before (in #3505):

```
5145705 pyodide.asm.data
1204075 pyodide.asm.js
8862216 pyodide.asm.wasm
```

After:

```
5145705 pyodide.asm.data
1346524 pyodide.asm.js
8905514 pyodide.asm.wasm
```

2) Emscripten draws everything into `Module.canvas`, but the canvas attribute is not set automatically (which makes sense as we don't output any HTML), so it is the user's job to set it manually.

For now, I am thinking of just mentioning it in the FAQ entry, "you need to set pyodide._module.canvas = ...". But it would be probably nice to have an API to set canvas, as pyodide._module is a private attribute.

### Checklists

- [x] Add a [CHANGELOG](https://github.com/pyodide/pyodide/blob/main/docs/project/changelog.md) entry
- [x] Add / update tests
- [x] Add new / update outdated documentation

### Demo

https://ryanking13.github.io/pyodide-pyxel-test

(mostly borrowed from the pyxel repository: https://github.com/kitao/pyxel/tree/main/wasm)

[tool.mypy]
python_version = "3.10"
mypy_path = ["src/py", "pyodide-build"]
show_error_codes = true
warn_unreachable = true
enable_error_code = ["ignore-without-code", "redundant-expr", "truthy-bool"]
plugins = ["pydantic.mypy"]

# Strict checks
warn_unused_configs = true
check_untyped_defs = true
disallow_any_generics = true
disallow_subclassing_any = false
disallow_untyped_calls = false
disallow_untyped_defs = false
disallow_incomplete_defs = true
disallow_untyped_decorators = true
no_implicit_optional = true
warn_redundant_casts = true
warn_unused_ignores = true
warn_return_any = false
no_implicit_reexport = true
strict_equality = true

[[tool.mypy.overrides]]
module = [
  "_pyodide_core",
  "docutils.parsers.rst",
  "js",
  "loky",
  "matplotlib.*",
  "PIL.*",
  "pyodide_js",
  "pytest_pyodide",
  "ruamel.yaml",
  "termcolor",
  "test",
  "tomli",
  "tomllib",
  "typer",
  "virtualenv",
]
ignore_missing_imports = true

[tool.ruff]
select = [
  "B0",     # bugbear (all B0* checks enabled by default)
  "B904",   # bugbear (Within an except clause, raise exceptions with raise ... from err)
  "B905",   # bugbear (zip() without an explicit strict= parameter set.)
  "C9",     # mccabe complexity
  "E",      # pycodestyles
  "W",      # pycodestyles
  "F",      # pyflakes
  "I",      # isort
  "PGH",    # pygrep-hooks
  "PLC",    # pylint conventions
  "PLE",    # pylint errors
  "UP",     # pyupgrade
]
ignore = ["E402", "E501", "E731", "E741"]
# line-length = 219  # E501: Recommended goal is 88 to match black
target-version = "py311"

[tool.ruff.per-file-ignores]
"src/py/_pyodide/_base.py" = [
  "PGH001",  # No builtin `eval()` allowed
]
"src/tests/test_jsproxy.py" = [
  "PGH001",  # No builtin `eval()` allowed
]
"src/tests/test_typeconversions.py" = [
  "PGH001",  # No builtin `eval()` allowed
]
"tools/*" = [
  "B008",  # Do not perform function call `typer.Optional` in argument defaults
]

[tool.ruff.flake8-bugbear]
extend-immutable-calls = ["typer.Argument", "typer.Option"]

[tool.ruff.isort]
known-first-party = [
  "pyodide",
  "pyodide_js",
  "micropip",
  "pyodide_build",
  "_pyodide",
  "js",
]
known-third-party = [
  "build",
]

[tool.ruff.mccabe]
max-complexity = 31  # C901: Recommended goal is 10

[tool.pytest.ini_options]
norecursedirs = [
    ".artifacts",
    "build",
    "cpython",
    "emsdk",
]
addopts = '''
--doctest-modules
--ignore="packages/matplotlib/src"
--ignore-glob="**/dist/"
--tb=short
--dist-dir=dist'''
testpaths = [
    "src",
    "pyodide-build",
    "packages",
]
asyncio_mode = "strict"

[tool.pyodide]

[tool.mypy]
python_version = "3.10"
mypy_path = ["src/py", "pyodide-build"]
show_error_codes = true
warn_unreachable = true
enable_error_code = ["ignore-without-code", "redundant-expr", "truthy-bool"]
plugins = ["pydantic.mypy"]

# Strict checks
warn_unused_configs = true
check_untyped_defs = true
disallow_any_generics = true
disallow_subclassing_any = false
disallow_untyped_calls = false
disallow_untyped_defs = false
disallow_incomplete_defs = true
disallow_untyped_decorators = true
no_implicit_optional = true
warn_redundant_casts = true
warn_unused_ignores = true
warn_return_any = false
no_implicit_reexport = true
strict_equality = true

[[tool.mypy.overrides]]
module = [
  "_pyodide_core",
  "docutils.parsers.rst",
  "js",
  "loky",
  "matplotlib.*",
  "PIL.*",
  "pyodide_js",
  "pytest_pyodide",
  "ruamel.yaml",
  "termcolor",
  "test",
  "tomli",
  "tomllib",
  "typer",
  "virtualenv",
]
ignore_missing_imports = true

[tool.ruff]
select = [
  "B0",     # bugbear (all B0* checks enabled by default)
  "B904",   # bugbear (Within an except clause, raise exceptions with raise ... from err)
  "B905",   # bugbear (zip() without an explicit strict= parameter set.)
  "C9",     # mccabe complexity
  "E",      # pycodestyles
  "W",      # pycodestyles
  "F",      # pyflakes
  "I",      # isort
  "PGH",    # pygrep-hooks
  "PLC",    # pylint conventions
  "PLE",    # pylint errors
  "UP",     # pyupgrade
]
ignore = ["E402", "E501", "E731", "E741"]
# line-length = 219  # E501: Recommended goal is 88 to match black
target-version = "py311"

[tool.ruff.per-file-ignores]
"src/py/_pyodide/_base.py" = [
  "PGH001",  # No builtin `eval()` allowed
]
"src/tests/test_jsproxy.py" = [
  "PGH001",  # No builtin `eval()` allowed
]
"src/tests/test_typeconversions.py" = [
  "PGH001",  # No builtin `eval()` allowed
]
"tools/*" = [
  "B008",  # Do not perform function call `typer.Optional` in argument defaults
]

[tool.ruff.flake8-bugbear]
extend-immutable-calls = ["typer.Argument", "typer.Option"]

[tool.ruff.isort]
known-first-party = [
  "pyodide",
  "pyodide_js",
  "micropip",
  "pyodide_build",
  "_pyodide",
  "js",
]
known-third-party = [
  "build",
]

[tool.ruff.mccabe]
max-complexity = 31  # C901: Recommended goal is 10

[tool.pytest.ini_options]
norecursedirs = [
    ".artifacts",
    "build",
    "cpython",
    "emsdk",
]
addopts = '''
--doctest-modules
--ignore="packages/matplotlib/src"
--ignore-glob="**/dist/"
--tb=short
--dist-dir=dist'''
testpaths = [
    "src",
    "pyodide-build",
    "packages",
]
asyncio_mode = "strict"

[tool.pyodide]
