Changes

Make CodanRunner progress monitor work a bit better (#768)

The progress monitor didn't show which file was being analyzed properly.

Also, the work units didn't seem to be counted in a good way because the
progress bar would stay stuck at like 1%. The fix in this commit for that is
not perfect as it gives equal weight to all resources on a same level until
further split into sub monitors. It still works quite a bit better without
requiring more heavy changes.

Also fix usage of deprecated SubProgressMonitor.