feat: Disable slash commands for encrypted rooms (#32548)

.changeset/popular-bulldogs-accept.md

apps/meteor/client/lib/chats/ChatAPI.ts

apps/meteor/client/lib/chats/flows/sendMessage.ts

apps/meteor/client/views/room/composer/ComposerBoxPopup.tsx

...ient/views/room/composer/ComposerBoxPopupSlashCommand.tsx

apps/meteor/client/views/room/composer/ComposerMessage.tsx

...teor/client/views/room/composer/messageBox/MessageBox.tsx

...meteor/client/views/room/contexts/ComposerPopupContext.ts

...eor/client/views/room/providers/ComposerPopupProvider.tsx

apps/meteor/tests/e2e/e2e-encryption.spec.ts

packages/i18n/src/locales/en.i18n.json