Add support for hiding videos (#29496)

* start hide

* Move useSettingsValueWithSetter to useSettings

* Add new setting showMediaEventIds

* Add a migration path

* Add an action button to hide settings.

* Tweaks to MImageBody to support new setting.

* Fixup and add tests

* add description for migration

* docs fixes

* add type

* i18n

* appese prettier

* Add tests for HideActionButton

* lint

* lint

* First pass at support for previewing/hiding images.

* Add a test for video files.

* First pass at supporting hiding video files.

* Use a hook for media visibility.

* Drop setting hook usage.

* Fixup MImageBody test

* Fixup tests

* Support functional components for message body rendering.

* Add a comment

* Move props into IProps

* Use new wrapping logic

* lint

* fixup

* allow for a delay for the image to render

* remove .only

* lint

* Fix jest test

* Fixup tests.

* make tests happy

* Improve comments

* review fixes

* unbreak test

test/unit-tests/components/views/messages/__snapshots__/MImageBody-test.tsx.snap

@@ -41,9 +41,6 @@ exports[`<MImageBody/> should generate a thumbnail if one isn't included for ani
             GIF
           </p>
         </div>
-        <div
-          style="height: 50px; width: 40px;"
-        />
       </div>
     </a>
   </div>
@@ -77,9 +74,6 @@ exports[`<MImageBody/> should show a thumbnail while image is being downloaded 1
       <div
         style="max-height: 50px; max-width: 40px;"
       />
-      <div
-        style="height: 50px; width: 40px;"
-      />
     </div>
   </div>
 </div>