Toolchain becomes package set part2

This is mostly a search and replace exercise (and thus probably correct). (Individual commits deal with kind-of single functions, and their associated tests.)

More complicated changes I have tried to move into separate merge requests.

tests.py

@@ -239,7 +239,9 @@ def test_install_environment_zlib():
     #         "cp -r foss2021a-mpi fuss1999a", shell=True, capture_output=True
     #     )
     # add zlib as a spec to global_generic
-    with open(package_set_src_dir / "global_generic" / "global_packages.list", "w") as f:
+    with open(
+        package_set_src_dir / "global_generic" / "global_packages.list", "w"
+    ) as f:
         f.write("zlib@1.2.13 \n")
 
     # add zlib to whitelist of module creation file by replacing anaconda3%gcc@10.2.1