Completions in props / yml that use 'simpleCompletion' should highlight the search term

There are still a few places that use ICompletionFactory.simplecompletion to create completion for list of values.

These completions therefore only use plaintext and do not highlight the search term like the other ones do.

We should fix this (probably by fixing implementation of 'simple completion' to do the nicer / fancier thing).