Add filters to Find in Files, to ignore Code, Strings, or Comments for find/replace

[Wierdox]

Partially supersedes #67796
Partially addresses Proposal #563

PR: For Find in Files, add filters to include/exclude Code, Strings, or Comments from your search results.

See it in action:

godot.windows.editor.x86_64_B5vbC8DonX.webm

Notes:

• Multiline string/comment aware, including mid line usage like func pie(/*old_param,*/ new_param);.
• "Language Agnostic".
  • Right now it either chooses gdscript # or c style // /**/, which as far as I'm aware are the only other languages(gdshader, csharp) supported in the editor. Maybe we could expose an option so users can add delimiters.
• Should not affect search speed if you leave everything enabled, implementation wise it's opt-in ignores.
• Find and Replace for Code Editor toolbar is not affected in this PR, it could be added in a follow up PR.
  • This is primarily due to the Code Editor using TextEdit to handle and draw the search highlights, which we can't do much about unless we copy pasta a lot of code or add coding related flags to TextEdit::SearchFlags. The latter of which was said to be avoided in the superseded PR.
  • Also, if we can squeeze this into 4.4, I think it's preferable to having to wait longer to also figure out how to make it work for local Find and Replace toolbar.
• Uses the phrase "Inside:" on its own line. You could also put them alongside "Match Case" and "Whole Words", but it causes the prompt to widen in a way that makes it more ugly I think.
• Strings filter is just a bonus while I was working on it, it could be removed if it's seen as not very useful. I for one don't have a use for it, but I saw a comment on the superseded PR bring it up.

[Wierdox]

Related to #75607, which replaces a bunch of internal functions, adds a file-extension-aware scanner, and allows .tscn files to be scanned for built-in scripts by default.