* fix(toolbar): accessibilityLabel should be translatable.

This commit adds a helper property to get the accessibilityLabel of an item,
providing a translation if one is available. This mimics the behavior of
label and tooltip.

* fix(toolbar) 'hangup' button accessibilityLabel i18n

* fix(toolbar) 'mute' button accessibilityLabel i18n

* fix(toolbar) 'videomute' button accessibilityLabel i18n

* fix(toolbar) 'moreActions' button accessibilityLabel i18n

* fix(toolbar) 'shareRoom' button accessibilityLabel i18n

* fix(toolbar) 'audioRoute' button accessibilityLabel i18n

* fix(toolbar) 'toggleCamera' button accessibilityLabel i18n

* fix(toolbar) 'audioOnly' button accessibilityLabel i18n

* fix(toolbar) 'roomLock' button accessibilityLabel i18n

* fix(toolbar) 'pip' button accessibilityLabel i18n

* fix(toolbar) 'invite' button accessibilityLabel i18n

* fix(toolbar) 'raiseHand' button accessibilityLabel i18n

* fix(toolbar) 'chat' button accessibilityLabel i18n

* fix(toolbar) 'shareYourScreen' button accessibilityLabel i18n

* fix(toolbar) 'fullScreen' button accessibilityLabel i18n

* fix(toolbar) 'sharedvideo' button accessibilityLabel i18n

* fix(toolbar) 'document' button accessibilityLabel i18n

* fix(toolbar) 'speakerStats' button accessibilityLabel i18n

* fix(toolbar) 'feedback' button accessibilityLabel i18n

* fix(toolbar) 'shortcuts' button accessibilityLabel i18n

* fix(toolbar) 'recording' button accessibilityLabel i18n

* fix(toolbar) 'settings' button accessibilityLabel i18n

* fix(welcomepage) accessibilityLabels i18n

* fix(toolbar) 'info' button accessibilityLabel i18n

* fix(i18n): Add translation to various aria-label property values.

* fix(i18n): Differentiate between overflow menu and button.

Fragment now works on both React and React Native, so use it.

It allows for specifying an override style collection which is applied when the
button is disabled.

- 5 buttons in the (now single) toolbar
- Overflow menu in the form of a BottomSheet
- Filmstrip on the right when in wide mode

Contributing all buttons in one place goes against the designs that we
set out at the beginning of the project's rewrite and that multiple of
us have been following since then.