Invalidate Visible Range, Responsive Language Update

Updates the visible set of indices when text storage happens, fixing the linked issue.
When setting a new language on the highlighter, adds a small "reset" that clears all current highlights. This makes the language update feel snappier, as the user receives immediate feedback. Before the ts parser could take a few seconds to begin highlighting, so there would be a delay making it seem like the language update was not happening.
Adds a missing throw to the tree-sitter client that made edits always run synchronously (didn't feel big enough for a whole PR, found while debugging).
Only updates the font if the font is new, making text layouts occur much less frequently (also doesn't feel big enough for a separate PR)

CodeEditApp / CodeEditSourceEditor