Text Notes: add a way to move up and down text lines via a keyboard shortcut

[adoriandoran]

Sometimes, moving text lines up and down is very handy, such as when reordering a to do list.

Ideally, this functionality could use 'Alt + Up Arrow' to move a line upwards and 'Alt + Down Arrow' to move it downwards, similar to the behavior in Visual Studio Code.

[eliandoran]

It's been requested since 2021 on upstream for todo lists: ckeditor/ckeditor5#9097

Unfortunately, there's been no update since then.