Handling for reserved Python keywords as JsProxy attrs. Resolves #3615. Things like `from` and `finally` are reserved keywords in Python and so `a.finally` 
is a `SyntaxError`. This automatically reroutes `a.from_` on a `JsProxy` to refer to `a.from` so it
can be used reasonably conveniently from Python.

### 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- [x] Add new / update outdated documentation

from pytest_pyodide import run_in_pyodide


@run_in_pyodide(
    packages=[
        "rebound",
        "numpy",
    ]
)
def test_integrate(selenium):
    import numpy
    import rebound

    sim = rebound.Simulation()
    sim.add(m=1)
    sim.add(m=1e-3, a=1)
    sim.add(m=1e-3, a=2)
    sim.integrate(10)

    assert numpy.fabs(sim.t - 10.0) < 1e-10, "Orbit integration not working"
    return None

from pytest_pyodide import run_in_pyodide


@run_in_pyodide(
    packages=[
        "rebound",
        "numpy",
    ]
)
def test_integrate(selenium):
    import numpy
    import rebound

    sim = rebound.Simulation()
    sim.add(m=1)
    sim.add(m=1e-3, a=1)
    sim.add(m=1e-3, a=2)
    sim.integrate(10)

    assert numpy.fabs(sim.t - 10.0) < 1e-10, "Orbit integration not working"
    return None
