Find in Files results semi-broken after canceling search bar

[peterflynn]

1. Run a Find in Files search that turns up some results
2. Open the Find in Files bar again, but press Esc or click out to close it before running a search
3. Make an edit that would add or remove a search result
4. In the search results panel at bottom, click one of the file headings to toggle it

Result:
3 - results don't update
4- exception thrown

This is because _doFindInFiles() resets the search state immediately, instead of waiting until the search is begun. We should either move that code later, or close the results panel as soon as the Find in Files bar is reopened.

[pthiess]

Last reviewed for 1.0 milestone added.

[njx]

Reviewed. Leaving in for 1.0. However, if we need to do some refactoring around this, we should consider how it affects other issues like #6617 (which is hard to fix for Find in Files right now because of the separation between module-global and dialog instance state) and the discussion in #7445.

[njx]

Reassigning to me. This isn't fixed yet in my branch, but should be easy to fix.

[njx]

Fix is in #8171