Lexical: Made list selections & intendting more reliable

- Added handling to not include parent of top-most list range selection
  so that it's not also changed while not visually part of the
  selection range.
- Fixed issue where list items could be left over after unnesting, due
  to empty checks/removals occuring before all child handling.
- Added node sorting, applied to list items during nest operations so
  that selection range remains reliable.