Global configuration flag for media previews (#29582)

* Modify useMediaVisible to take a room.

* Add initial support for a account data level key.

* Update controls.

* Update settings

* Lint and fixes

* make some tests go happy

* lint

* i18n

* update preferences

* prettier

* Update settings tab.

* update screenshot

* Update docs

* Rewrite controller

* Rewrite tons of tests

* Rewrite RoomAvatar to be a functional component

This is so we can use hooks to determine the setting state.

* lint

* lint

* Tidy up comments

* Apply media visible hook to inline images.

* Move conditionals.

* copyright all the things

* Review changes

* Update html utils to properly discard media.

* Types fix

* Fixing tests that break settings getValue expectations

* Fix logic around media preview calculation

* Fix room header tests

* Fixup tests for timelinePanel

* Clear settings in matrixchat

* Update tests to use SettingsStore where possible.

* fix bug

* revert changes to client.ts

* copyright years

* Add header

* Add a test for MediaPreviewAccountSettingsTab

* Mark initMatrixClient as optional

* Improve on types

* Ensure we do not set the account data twice.

* lint

* Review changes

* Ensure we include the client on rendered messages.

* Fix test

* update labels

* clean designs

* update settings tab

* update snapshot

* copyright

* prevent mutation

src/i18n/strings/en_EN.json

@@ -525,6 +525,7 @@
         "message_timestamp_invalid": "Invalid timestamp",
         "microphone": "Microphone",
         "model": "Model",
+        "moderation_and_safety": "Moderation and safety",
         "modern": "Modern",
         "mute": "Mute",
         "n_members": {
@@ -2668,12 +2669,10 @@
             "unable_to_load_msisdns": "Unable to load phone numbers",
             "username": "Username"
         },
-        "image_thumbnails": "Show previews/thumbnails for images",
         "inline_url_previews_default": "Enable inline URL previews by default",
         "inline_url_previews_room": "Enable URL previews by default for participants in this room",
         "inline_url_previews_room_account": "Enable URL previews for this room (only affects you)",
         "insert_trailing_colon_mentions": "Insert a trailing colon after user mentions at the start of a message",
-        "invite_avatars": "Show avatars of rooms you have been invited to",
         "jump_to_bottom_on_send": "Jump to the bottom of the timeline when you send a message",
         "key_backup": {
             "backup_in_progress": "Your keys are being backed up (the first backup could take a few minutes).",
@@ -2732,6 +2731,14 @@
         "labs_mjolnir": {
             "dialog_title": "<strong>Settings:</strong> Ignored Users"
         },
+        "media_preview": {
+            "hide_avatars": "Hide avatars of room and inviter",
+            "hide_media": "Always hide",
+            "media_preview_description": "A hidden media can always be shown by tapping on it",
+            "media_preview_label": "Show media in timeline",
+            "show_in_private": "In private rooms",
+            "show_media": "Always show"
+        },
         "notifications": {
             "default_setting_description": "This setting will be applied by default to all your rooms.",
             "default_setting_section": "I want to be notified for (Default Setting)",