Add method to provide a default way of formatting descriptions
Enable CloseChar auto edit
Improve pair element searching logic in `CloseMatchingPair`

The new logic is easier to understand and correct and contrast to the
previous one, which was not correct in some edge cases.
Add auto edit that adds closing curly brace to end of block

I can't say how I like this feature. It is just a heuristic because
we can't really parse the document in order to find the end of an
expression but it should work fine in most cases nevertheless.

Fixes #1002133
Update pref store references in `ScalaSourceViewerConfiguration`
Update pref store references in scanner classes

There was no need to use multiple pref stores, only one is used now.