Move: first move semantic for text

[MeneDev]

Experimenting with move semantics

Current status:

• simple moves of single elements seem to work now
• new action 'mov' to encode moves in a single action
  • uses key and child to encode operation
  • moves from child to key

Untested:

• multiple moves
• concurrent moves
• anything more complex than moving a single character once

Still figuring out:

• moves are encoded as insert/remove on edits level, not sure if that works in the general case

Planned:

• somehow define a range of elements to create an atomic move of a whole range