Cleanup: Disable Invert options in Light Mode

[JacksonZ03]

Cleanup

Light mode currently is cluttered and there are some really unnecessary bits that both clutter the UI and the codebase itself.

First of all, the whole point of this chrome extension is to add dark mode - which naturally assumes that Google Docs is already in "Light mode".

This makes the Light Mode setting entirely redundant (apart from perhaps slight UI shading customisations that the user can change).

But besides that point, with the current lightmode, it has the invert options which invert black text to white - completely useless when text is naturally black in Light mode anyways.

And secondly, there is also an invert option that is completely useless since all it does in lightmode is invert the colored text - why a user would want to deliberately mess up their own document's colors?

So in this commit, I hide the Invert options entirely in Light mode and also remove the invert option in the advanced settings. This keeps the existing behaviour in the UI and cuts down the unnecessary bloat in the codebase.

[JacksonZ03]

This PR does have conflicts with the feature branch #111 since I branched off from main when implementing this commit, but I'll clean up and resolve the commit conflicts once #111 is merged and convert the PR out of draft.

[waymondrang]

Hello @JacksonZ03, just wanted to poke this and let you know that #111 has been merged. Let me know if you're still interested in working on this!

[JacksonZ03]

ah, yes. I want to keep this in drafts for now, I'm in a busy period right now, but when I have more time, I'll resume progress on this. Of course, if you want to implement this idea, you don't have to wait on me. But if not, don't worry about merge conflicts for this one, when I come back, I'll resolve them.