[debt] improve the internals of the suggestion contribution

[jrieken]

Over the years we have accumulated debt in the internals of the suggest feature. Let's collect what we have already cleaned up and what left to do.

• move overwiteBefore and overwriteAfter from ISuggestResult to ISuggestion - @aeschli
• remove Suggestion.highlights and move it correctly in to the view model
• improv perf when filtering down a list of suggestion by using the tree properly - @joaomoreno

[jrieken]

@aeschli I'd be nice if you can update the html and JSON intellisense to use the textEdit

[joaomoreno]

👍

[jrieken]

@joaomoreno i have fixed the problem of disappearing highlights when focusing a suggestion

[joaomoreno]

@aeschli Only overwriteBefore and overwriteAfter left...!

[aeschli]

@joaomoreno I'll work on it ASAP

[jrieken]

💃