* For #4281: small ToolbarMenu refactor

This makes it easier to see how items are ordered in the menuItems list

* For 4281: add QAB buttons to menu

* For 4281: removed menu back button per mocks

I double checked with UX, and we'll be relying on the hardware back button for its functionality

* For 4281: add content descriptions for bookmarking

* For 4281: updated BrowserToolbarController for new functionality

* For 4281: provided simple dependencies to browser controller

More complex changes will be in a following commit, for review readability

* For 4281: move toolbar controller dependencies up to BaseBrowserFragment

The functionality they control is being moved into the toolbar menu, which is shared by both normal tabs and custom ones

* For 4281: removed (now unused) code related to QAB

* For 4281: fix test compilation after QAB removal

Tests still need to be expanded to include added functionality

* For 4281: updated menu to show if url is bookmarked

This sloppy workaround is required because TwoStateButton requires that `isInPrimaryState` be a synchronous call, and checking whether or not the current site is bookmarked is quite slow (10-50 MS, in my tests).  After days of work and many attempted solutions, this was the least abhorrent among them.

https://github.com/mozilla-mobile/android-components/issues/4915 was opened against AC to evaluate potentially supporting async `isInPrimaryState` functions.
https://github.com/mozilla-mobile/fenix/issues/6370 was opened against Fenix to investigate the unexpectedly slow call to `BookmarkStorage`.

* For 4281: update reader mode switch

* For 4281: selectively show/hide menu items

* For 4281: add reader mode appearance

* For 4281: update bookmark button when it is clicked

* For 4281: removed unused QAB code

* For 4281: removed QAB robot, updated UI tests

* For 4281: removed QuickActionSheet metrics

Since this behavior now lives in the toolbar, it is tracked via Event.BrowserMenuItemTapped

* For 4281: fixed lint errors

* For 4281: add new strings for buttons added to menu

This is necessary because the location change (from QAB to toolbar menu) could affect the grammar in some languages

* For 4281: remove outdated TODOs

* For 4281: removed QAB container

* For 4281: removed back button reference from UI test

This button no longer exists

* For 4821: Fixes a visual defect (extra padding on top of toolbar)

* For 4281: update copy on reader mode

* For 4281: fixed review nits