Restore ability to toggle sidebar via action click in MV3

[fregante]

What does this PR do?

I think I found a way to restore toggling of the extension via browser action.

Drawbacks

• It relies on a race condition but it seems to work decently, we can give it a go since it's so simple.
• The sidePanel can only be closed from within, so the close action only works if it's already fully loaded
  • Closing the sidePanel via sidePanel.setOptions has further drawbacks
    • sidePanel API: sidePanel.close() and sidePanel.toggle() w3c/webextensions#521

Demo

Screen.Recording.mov

Checklist

• Add tests
• New files added to src/tsconfig.strictNullChecks.json (if possible)
• Designate a primary reviewer: @grahamlangford

Follows

• Follows #7228: Add support for sidePanel in the MV3 build #7354

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (ed0e25b) 72.61% compared to head (fec762d) 72.61%.

❗ Current head fec762d differs from pull request most recent head 07863f7. Consider uploading reports for the commit 07863f7 to get more accurate results

Files	Patch %	Lines
src/background/browserAction.ts	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7429      +/-   ##
==========================================
- Coverage   72.61%   72.61%   -0.01%     
==========================================
  Files        1210     1210              
  Lines       37821    37822       +1     
  Branches     7098     7098              
==========================================
  Hits        27464    27464              
- Misses      10357    10358       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[grahamlangford]

I hate it. But it works, and like you said it's simple. It's insane to me that this isn't supported. I believe you have an issue open requesting this as a feature?

[github-actions]

No loom links were found in the first post. Please add one there if you'd like to it to appear on Slack.

Do not edit this comment manually.

[fregante]

Yes the issue is in the PR description. I don't expect the API to appear within the next 6 months so we'll have to live with it for now. Worst case scenario we'll remove the feature and update the docs only if it causes issues.