Changes to the enterprise enhanced context panel:

- Pluralizes repo/repos in the repo tree view summary line
- Updates counts in the repo tree view summary line
- Mentions the number of ignored repos in the repo tree view summary
line (if any)
- Adds a help tooltip with a link to documentation
- Removes the help button from the right-hand side toolbar
- Clicking outside the repo picker popup accepts the edits instead of
cancelling them
- Alt-tabbing while the repo picker popup is open does not dismiss it

Part of #1322

## Test plan

Tested manually.

1. Run with `CODY_JETBRAINS_FEATURES=cody.feature.internals-menu=true`
2. Sign into an Enterprise account
3. Verify the repo picker is collapsed, one line and the edit pencil is
visible
4. Hover the repo picker and verify the tooltip, opening the link goes
to context documentation

![Screenshot 2024-05-10 at 20 23
52](https://github.com/sourcegraph/jetbrains/assets/55120/e3f30e14-a740-445d-bdeb-510cd98e98a8)

5. Add repos and verify the summary line language updates, pluralization
is correct, etc.
6. Use Internals, Testing: Cody Ignore and ignore some repositories,
check the "ignored" language updates, etc.

![Screenshot 2024-05-10 at 20 25
19](https://github.com/sourcegraph/jetbrains/assets/55120/023d38f7-6f41-4563-87ba-1d7093c796bd)

7. Verify the details of adding repositories with the pencil:
    - Change text, press ESC, repo list should *not* update
    - Change text, press cmd-enter, repo list should update
- Change text, click outside popup, repo list *should* update (new
behavior)

8. Open the pencil popup, verify that cmd-tab/alt-tab away from IntelliJ
and back does not close the popup