Generalizing the text input component

[Bios-Marcel]

Currently the message editor is being used for the command input as well. That is convenient as it requires less code, however, the message input support some features that the command input simply doesn't need:

• Mentioning
• Multiline support

There should be a general editor component that has the following features:

• Autocomplete (Tab & Popup like the mention dialog. This feature could then be used for emojis, mentions, commands and more!)
• General text editing (The usual stuff you'd expect)
• Optional line breaking

It should be easy to extend it using composition.