forked from github/szkolny

* [UI/Messages] Add draft text styling support. * [UI/Messages] Improve mid-word span styling. Restore subscript and superscript styles. * [UI/Messages] Replace framework spans with custom classes on replying. * [Messages/Compose] Move UI-related code to separate classes. * [UI/Messages] Disable text style buttons when not in focus. * [Messages/Compose] Disable text styling on Vulcan. * [UI/Messages] Add hint toasts to text style toggles. * [UI/Messages] Add button to clear text styling. * [Messages/Compose] Fix XML formatting.