RFR: 2331: Improve review notes [v4]

[Pavel Rappo]

> There are two variants of a note that can be added to an item in the "Reviewers" list of a PR body:
> 
>   - 🔄 Re-review required ...
>   - ⚠️ Review applies to ...
> 
> That note may confuse or draw unneeded attention to the PR body.
> 
> Firstly, as a result of recently integrated [SKARA-2312][], "⚠️ Review applies to ..." is also added to an item (i.e. review) that applies to the head of the PR. Secondly, "🔄 Re-review required (review applies to ..." may be present for some items even though a PR has the green "ready" label.
> 
> [SKARA-2312]: https://bugs.openjdk.org/browse/SKARA-2312

Pavel Rappo has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - Respond to feedback
 - Merge branch 'master' into 2331
 - Don't special-case wrong target or missing commit
   
   After out-of-band conversation with @zhaosongzs, we decided to drop
   useStaleReviews check.
 - Avoid emojis and "required" when a PR is ready
 - Re-indent code
 - Don't add "Re-review required" if reviewed
   
   If review requirements are fully satisfied, don't add "Re-review
   required (review applies to ..." for stale reviews; instead, add
   "Review applies to ..."
 - Don't add "Review applies to" to the head of a PR

-------------

Changes:
  - all: https://git.openjdk.org/skara/pull/1679/files
  - new: https://git.openjdk.org/skara/pull/1679/files/15aba4b6..cd128621

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=skara&pr=1679&range=03
 - incr: https://webrevs.openjdk.org/?repo=skara&pr=1679&range=02-03

  Stats: 176 lines in 12 files changed: 101 ins; 19 del; 56 mod
  Patch: https://git.openjdk.org/skara/pull/1679.diff
  Fetch: git fetch https://git.openjdk.org/skara.git pull/1679/head:pull/1679

PR: https://git.openjdk.org/skara/pull/1679