Mark all threads as read button (#12378)

* Mark all threads as read button

* Wrap in TooltipProvider and update snapshots

* Remove TooltipProvider wrapper: just add it to the test

* Add some more tests

* Add test for no-room-context handler because sonarcloud

* Add playwright test

* Make assertNoTacIndicator wait

* Use dedicated useMatrixClientContext function

Co-authored-by: Florian Duros <florianduros@element.io>

* Use dedicated useRoomContext function

Co-authored-by: Florian Duros <florianduros@element.io>

* Compound spacing variables

Co-authored-by: Florian Duros <florianduros@element.io>

* Compound spacing variables

Co-authored-by: Florian Duros <florianduros@element.io>

* Imports

* Use createTestClient()

* Add function to utils

* Use mkRoom

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Co-authored-by: Florian Duros <florianduros@element.io>

src/i18n/strings/en_EN.json

@@ -3151,6 +3151,7 @@
         "empty_heading": "Keep discussions organised with threads",
         "empty_tip": "<b>Tip:</b> Use “%(replyInThread)s” when hovering over a message.",
         "error_start_thread_existing_relation": "Can't create a thread from an event with an existing relation",
+        "mark_all_read": "Mark all as read",
         "my_threads": "My threads",
         "my_threads_description": "Shows all threads you've participated in",
         "open_thread": "Open thread",