Improves tab switching and tab related perf

[bridiver]

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

fix #8853
Fixes #8851

Test Plan:

Reviewer Checklist:

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run indivually or as a suite ref

[bsclifton]

Issues noticed by @NejcZdovc and I during testing:

Issues which happen because of this PR

• 1. Having a pinned tab causes new tabs to insert at index 0
• Pin a tab
• Hit the new tab button

These happen in master

• 1. tab preview stops working

• hit cmd + T a bunch of times (like 5 - 10)

• hover over tabs that were opened, one at a time

• notice preview doesn’t show for some tabs. BUT… clicking tab, page had loaded actually

• 2. Window closed after tear off tabs #8878

• Window 1: have two tabs

• Drag one out

• it creates Window 2 and closes Window 1

• 3. After tearing off a tab, the tabs themselves aren't rendered

• Tear a tab off

• inspect the window. If the titles are rendering, try again

• if the titles are not showing, press shift + F8 to see the Muon dev tools

• You'll see the error: Unchecked runtime.lastError while running tabViewInternal.getTabID: Could not find guest

[NejcZdovc]

@luixxiul this will be in 0.15.30x

[bsclifton]

@bridiver @NejcZdovc can we rebase this against dev-channel?