New Issue: Update third-party-pkgs.py script to always use new map

16768, “daviditen”, “Update third-party-pkgs.py script to always use new map”, “2020-11-20T22:48:42Z”

Add all required mappings to the new map in generate_subdir_map() so we don’t require the branch here:

Remove that branch along with the get_all_pkgs() function.

Update any leftover variable settings to use bundled that make sense. For example CHPL_REGEXP=re2 -> CHPL_REGEXP=bundled.