Modify inline_autocomplete to fetch data from the backend

[xhero]

Inline autocomplete is what we use to autotype static data configured in the FormOptions, it needs to be extended so the data can come from the backend, and also so it can work as a target to autocomplete_extra. This is also used in GND editor where we do not need to fetch the master field. Initial implementation in 1c760e15807f440eff38d545709b78086ca238f9