feat: PR validation includes release worthiness notification (W-23251216)

[jfeingold35]

Previously, the validatePR.yml workflow only checked that a Pull Request's title and body both contained a string that looks liked it could conceivably be a GUS Work Item (i.e., W-\d{7,8} in title, and @W-\d{7,8}@ in body).

Now, the workflow enforces multiple things.

1. The Title contains a string that looks like it could be a work item.
2. The Body contains the same string from the Title, wrapped in @'s.
3. If those criteria are violated, a criteria tree is logged with checks and x's to show what you did wrong.
4. An additional Job has been added that, if none of the commits in the PR are feat: ___ or fix: ___, adds a comment to the PR saying, more or less, "this PR will not trigger a release, use 'fix' or 'feat' to do that; to silence additional messages like this, react with the 👀 emoji."

Criteria 1-3 are derived from #162 , a first attempt at this feature.
Criteria 4 was experimentally written and tested in #176 and #178.

This enhancement was done for @W-23251216@.