* 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.