Fix #7851: Tab selection for TabsBar interface is done after active website is loaded

[soner-yuksel]

Summary of Changes

This pull request fixes #7851

Submitter Checklist:

• Unit Tests are updated to cover new or changed functionality
• User-facing strings use NSLocalizableString()
• New or updated UI has been tested across:
  • Light & dark mode
  • Different size classes (iPhone, landscape, iPad)
  • Different dynamic type sizes

Test Plan:

• Enable Tabs Bar

• Load multiple tabs (+10 tabs etc)

• Remove the app from background if it is active

• Launch fresh

• Observe the active tab is selected after website is loaded

Screenshots:

RPReplay_Final1693949329.MOV

Reviewer Checklist:

• Issues include necessary QA labels:
  • QA/(Yes|No)
  • bug / enhancement
• Necessary security reviews have taken place.
• Adequate unit test coverage exists to prevent regressions.
• Adequate test plan exists for QA to validate (if applicable).
• Issue and pull request is assigned to a milestone (should happen at merge time).