Cherry-pick of 782ee47. That is probably over-aggressive, but it fixes
it.
Closes #40633
previously: #40744
---------
Co-authored-by: Yu Leng (from Dev Box) <yuleng@microsoft.com>
_targets #40504_
Major refactoring for #40113
This moves a large swath of the codebase to a `.Core` project. "Core"
doesn't have any explicit dependencies on "extensions", settings or the
current `MainListPage`. It's just a filterable list of stuff. This
should let us make this component a bit more reusable.
This is half of a PR. As I did this, I noticed a particular bit of code
for TopLevelVViewModels and CommandPaletteHost that was _very rough_.
Solving it in this PR would make "move everything to a new project" much
harder to review. So I'm submitting two PRs simultaneously, so we can
see the changes separately, then merge together.
Refactored ContextMenu into it's own control to allow displaying in
CommandBar and in response to right click on list items.
- Adds "critical" styling to context menu items flagged as `IsCritical`.
This will use the theme to style with correct color.
- Added `SeparatorContextItem` and modified `MoreCommands` to allow for
both `CommandContextItem`s and `SeparatorContextItem`s.
- Right clicking a list item with a context menu will open the context
menu at the position of the click and position the filter box at the top
of the context menu.
This PR covers:
- closes#38308
- closes#39211
- closes#38307
- closes#38261
