Lets the user configure how the property completion should happen.
There are two main modes: strict and loose (default)
On loose, the editor will suggest anything, not caring about the domain.
On strict, the editor will only suggest property that have a matching domain or anything if the
type could not be determined.
How Turtle/TriG prefix declarations should be written when the editor inserts
them (e.g. during prefix completion or the “add missing prefix” quick-fix).