Sidebar active tabs

[PressJump]

Fixes #146 Implementing Sidebar Background Active Tabs

[PressJump]

QA Requirements

• Sidebar

  • The sidebar exists
  • The settings and addons button are visible down the bottom
  • The bookmarks, history and synced tabs icons are in the sidebar
  • The sidebar can be resized properly
  • An installed extension will appear in the sidebar
  • Sidebar-Tabs is Loaded and has a button visible down the bottom
  • Sidebar-Tabs can add a sidebar item to the sidebar
  • Sidebar-Tabs can remove a sidebar item to the sidebar
  • The sidebar keeps tabs active while closed when the preference pulse.sidebar.keeptabsactive.enabled is set to true
  • The sidebar overwrites tabs when the preference pulse.sidebar.keeptabsactive.enabled is set to false

• Extensions

  • Tabliss is loading correctly
  • Tabliss does not have the webextention symbol in the title bar
  • uBlock origin is loading correctly
  • QRCode generator is loading correctly

• About dialog

  • The new about dialog is present
  • The dialog has not significantly changed

• Pocket

  • Pocket is not present in the browser

• Preferences

  • All tabs in preferences open
  • The "More from {Vendor}" option is not present
  • The sidebar preferences are present and work as expected

• Welcome experience

  • The import button opens the import wizard
  • The theme picker is present and works as expected
  • The search engine picker is present and works as expected

• Pulse theme

  • The tabs appear to be consistent

• Mozilla theme

  • The sidebar tabs are correct

• Useragent

  • The user agent is reporting as Mozilla Firefox

[PressJump]

Currently browsers do not keep up with new sidebar sizing on 107, and removed shortcuts still exist in the background. With changes coming with Sidebar Active Tabs, the QA checks will need an update too. In draft for now due to this.

[PressJump]

Removed shortcuts now get removed after restart of the browser. This is the case with every other loaded tab as well. Persistence is only kept when keepTabsActive is set to false.

[PressJump]

Welcome options for sidebar will be available on next PR.

[trickypr]

This will not be merged if it requires a browser restart to work correctly. Either:
a) Remove the preference
b) Add a preference observer and fix whatever ends up being broken that requires a browser restart

[PressJump]

Changed to draft until changes made, I am not too sure why it was not on draft already after last review.

[PressJump]

Preference now relies on observer, reloading the sidebar and removing any left over content and changes have been updated to sync with alpha.

[PressJump]

Yea sorry, forgot to lint.