[NEW] New Message Composer (#27566)

apps/meteor/app/emoji/client/lib/EmojiPicker.js

apps/meteor/app/lib/server/startup/settings.ts

...eteor/app/theme/client/imports/components/message-box.css

apps/meteor/app/threads/client/threads.css

.../meteor/app/ui-message/client/actionButtons/messageBox.ts

apps/meteor/app/ui-message/client/index.ts

...eor/app/ui-message/client/messageBox/createComposerAPI.ts

apps/meteor/app/ui-message/client/messageBox/messageBox.html

apps/meteor/app/ui-message/client/messageBox/messageBox.ts

...or/app/ui-message/client/messageBox/messageBoxAutogrow.ts

.../app/ui-message/client/messageBox/messageBoxFormatting.ts

...app/ui-message/client/messageBox/userActionIndicator.html

...r/app/ui-message/client/messageBox/userActionIndicator.ts

apps/meteor/app/ui-utils/client/lib/messageBox.ts

apps/meteor/app/ui-utils/client/lib/popover.js

apps/meteor/app/ui/client/lib/ChatMessages.ts

apps/meteor/app/ui/client/lib/UserAction.ts

...components/message/Attachments/FieldsAttachment/Field.tsx

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

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