Should I embed a related work section in the introduction, and how would I do this? I am in the final stage of completing a thesis.

Context: I propose a new knowledge representation to tackle information overload in science (E-Science, scientific communication, linked data). Specifically, I created a knowledge representation of scientific problems.

In the introduction, I motivate the need of the new artefact based on two things:
1. A general need for digital knowledge representations for automatic reasoning, being able to filter out relevant aspects of scientific work to make them findable,
2. The unavailability of a knowledge representation for a specific aspect of scientific work; namely, scientific problems ("challenges", "gaps").

Other approaches that present a digital knowledge representation of aspects of scientific work were included as related work, but they also exemplify that the aspect I focus on is missing.

Do I incorporate this related work in the introduction, or present them in a separate related work section?
Would it be better to state "To this day, no representations of scientific problems exist" in the introduction and show the other approaches in a separate related work section, or is it nicer to show these other approaches in the introduction first (by including a subsection with all related work - separate subsections per approach - what would the title of this subsection be?), to then base the motivation of creating this new representation in an "approach" subsection which contains the research questions?
The structure of your paper should make it attractive to read and easier to understand. So keeping to the common structure in your field is usually helpful, but not a dogma that should be obeyed when it's not useful.

Introduction -> Related Work -> Main Contributions is a pretty common start for CS writing, so making it a separate section would be the default option.

However, if you have to lean heavily on a literature discussion to motivate the need for your work, it can make more sense to pull them together into a single chapter, perhaps with subsections.