refactor(profile): drop extended-profile editing, keep right-panel display

Extended-profile fields (io.element.profile.*) are no longer edited in the
client, so remove the edit form and the dead code that came with it, keeping
only the read-only right-panel display (UserExtendedProfileInfo).

- Remove ExtendedProfileSettings (edit form) + its Settings integration and CSS
- Remove ExtendedProfileView (never-rendered, dead) + its CSS
- Inline the EXT_PROFILE_KEY_* constants into UserExtendedProfileInfo so it no
  longer depends on the deleted settings component
- Drop now-unused set/deleteExtendedProfileProperty from UserProfilesStore
- Prune dead settings|extended_profile_settings|* i18n keys (and the unused
  user_info.extended_profile header/not_provided keys) across all locales
- Regenerate _components.pcss
- Revert UserProfileSettings/AccountUserSettingsTab tests (+snapshot) to master,
  since their adaptations existed only for the removed edit form

apps/web/res/css/_components.pcss

@@ -235,7 +235,6 @@
 @import "./views/right_panel/_BaseCard.pcss";
 @import "./views/right_panel/_EmptyState.pcss";
 @import "./views/right_panel/_EncryptionInfo.pcss";
-@import "./views/right_panel/_ExtendedProfileView.pcss";
 @import "./views/right_panel/_ExtensionsCard.pcss";
 @import "./views/right_panel/_PinnedMessagesCard.pcss";
 @import "./views/right_panel/_RoomSummaryCard.pcss";
@@ -304,7 +303,6 @@
 @import "./views/rooms/wysiwyg_composer/components/_FormattingButtons.pcss";
 @import "./views/rooms/wysiwyg_composer/components/_LinkModal.pcss";
 @import "./views/settings/_AvatarSetting.pcss";
-@import "./views/settings/_ExtendedProfileSettings.pcss";
 @import "./views/settings/_FontScalingPanel.pcss";
 @import "./views/settings/_ImageSizePanel.pcss";
 @import "./views/settings/_IntegrationManager.pcss";