feature: new text editor with basic functionality

[mjulstein]

Initial work on new Text Editor:

Figma sketch

For the first iteration, the UI will be simplified.

• Only 1 language will be editable at a time.
• Select which language to edit in the sidebar, instead of toggling visibility of languages.
• No search functionality
• No flag icons

The first implementation will look something similar to what this image explains:

Functional requirements

The text editor should work with the new API's that uses the new simplified text format (plain key/value format)

• [x] Edit ID
• [x] Edit value
• [x] Add new entry (id+value)
• [x] Delete entry
• [x] Add language
  • [ ] Languages that is already added should be filtered out from the list of possible languages to add
• [x] Delete language
• [x] Toggle which language to edit
• [x] All changes should be autosaved on blur