TST/FIX: ArchiveSearchWidget Tests

[zdomke]

Adding tests for ArchiveSearchWidget and ArchiveResultsTableModel.

Fixing issues that came up during testing:

• In config.py & config.json:
  • Remove archiver_urls because I realized they aren't being used anywhere in the project and could cause confusion
• In archive_search.py:
  • Change the method of getting the logger to prevent getting a duplicate logger
  • Fix ArchiveResultsTableModel.rowCount implementation because it requires an argument when it should default to an empty QModelIndex
  • Populate ArchiveSearchWidget.archive_url_textedit with $PYDM_ARCHIVER_URL instead of hardcoding the URL
  • In ArchiveSearchWidget.request_archiver_info, make some wildcards work for 1+ characters instead of just 1 character

[zdomke]

I managed to mess up this PR pretty badly. Opening a different one instead. ¯\(ツ)/¯