Evaluate and migrate to composable toolbar

Evaluate and migrate to composable toolbar

Mozilla added a new composable toolbar: https://bugzilla.mozilla.org/show_bug.cgi?id=1950909

and apparently are making it default on in 144. So we want to look at it and likely adopt and migrate our toolbar changes to it

screenshot of composable toolbar

for 140 we did a fixup !1759 (merged) to ensure it's off that we'll likely want to change before esr-next if we adopt it

Was: Review Mozilla 1950909: [composable toolbar] Initial integration in Fenix

🔍 Bugzilla Audit

Bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1950909

Description

There was some refactor around browserToolbarView, so we had to comment some parts of our code (see 09bb6f05).

There are probably a few more related bugs to check.

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