General ChatInviteDialog optimisations
- Use avatar initial instead of "R" or "?"
- Use Fuse.js to do case-insensitive fuzzy search. This allows for better sorting of results as well as search based on weighted keys (so userId has a high weight when the input starts with "@").
- Added debounce of 200ms to prevent analysis on every key stroke. Fuse seems to degrade performance vs. simple, non-fuzzy, unsorted matching, but the debounce should prevent too much computation.
- Move the selection to the top when the query is changed. There's no point in staying mid-way through the items at that point.
