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

[daviditen]

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

chapel/util/chplenv/third-party-pkgs

Line 77 in 409d71b

if val in get_all_pkgs():

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.