Fix error highlighting in IDE.

[sampottinger]

Error highlighting is a bit broken (see #714).

Root cause: Depending on how the Problem is made, the error may be given relative to start of line or start of tab. Changed method names to indicate to users of Problems which one they are working with.

I think this may have been introduced in the language server support effort as Problems may be made without Editor available. The behavior in #714 appears to have started then but there was a delay before it showed up in production given how releases were done.

Resolution: I clarified the interface and gave client code ability to determine if they want / need a Problem to be placed relative to start of line or start of tab where each are more convenient in different contexts.

[sampottinger]

Hey @benfry! It looks like some ambiguity in Problem caused an issue when we implemented language server support that broke error highlighting. LMK if this looks good! Sorry I noticed something was off a while ago but I thought it was a theme issue and didn't have time to dig into exactly what was going on until today when I realized it wasn't just my local install. 😅

[sampottinger]

CC @SableRaf

[sampottinger]

Doing one bit of cleanup this morning but we should prioritize this

[sampottinger]

Cool did the clean up! Ready for review... I think it's probably best to have client code indicate which type of start offset it wants when interacting with a problem. I've tested the PDE... checking language server.

[sampottinger]

Yay! Confirmed language server working. :D

[sampottinger]

I know we don't have an imminent release but this is is getting in the way of a GSoC project. To make sure he can still finish on time / pass, I'm going to merge this to main but I won't make a release. Without this sorted, the error message rewriting isn't visible to the user.