Fix #7479: Use top page color sampling for status bar overlay view color

[kylehickinson]

Summary of Changes

This pull request fixes #7479

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:

• Verify visiting certain pages update the status bar background color to match headers (Note: YouTube's header is technically white, not black which is what you'd expect)
• Verify going back to NTP goes back to toolbar color
• Verify switching between tabs switches the colors accordingly
• Verify that when the top bar changes to a dark color that the status bar (time/wifi/etc.) shows white text (and that going to other places like tab switcher reverts back)
• Verify that none of the above happens when not using bottom bar

Screenshots:

GitHub	9to5Mac	TheVerge

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).