Fix #52590 - don't move focus when clicking the search details buttons with screenreader mode turned on.
Because NVDA sends click events instead of key events when pressing space.
Also update this dynamically for the search option buttons

Fix #52274 - don't move focus when clicking the find option buttons with screenreader mode turned on, because NVDA sends click events instead of key events when pressing space on a focused button

Fix #55556 - include wordSeparators in all search queries, so findTextInFiles can respect isWordMatch correctly

- avoid public modifier
- use Disposable where applicable
- fix some event handler leaks
- clean up some TODO@ben