Rename component source plugin configuration keys for clarity

Naming things is hard when you have multiple layers of indirection and similar things that are related to each other, as per both this issue itself *and* the title.

#2++, tried to clarify slightly :D

Bumping priority because this will continue to cause confusion otherwise.

@longwave, any chance you could get an initial MR up in the next few days, so that we can eliminate any further wasted minutes/hours on this confusion? 😇🙏

+1 for idea, but lots of tests not yet passing. Pushed one commit that I believe will fix many things, but not yet sure how many.