Externally-usable supervisor tool

[j-woz]

[rajeeja]

We can simplify the test script management (sif/non-sif,benchmark,cmp,dense, various prms etc.)

It can be split based on workflow//swift/<variations_of_sh/swift_files>

Also, need more help text around the usage:
2023-06-27 17:50:11 supervisor: usage: $ supervisor <SITE> <WORKFLOW> <TEST_SCRIPT>

[j-woz]

This is on branch issue-97