RFR: 2253: No need to check title mismatch between PR and JBS for additional issues

[Zhao Song]

Users can use command /issue to associate more issues with a pr. When processing an /issue command, skara bot would add a hidden marker like this "" in a comment. Later, in CheckRun, the pr bot would parse the hidden markers to get all additional issues and use them as keys in regularIssuesMap. The values of regularIssuesMap are jbs issues. Pr bot would check if the issue title matches between the title of the key(title in the hidden marker) and the title of the value(title in the jbs issue). If not, pr bot would add " ⚠️ Title mismatch between PR and JBS." to the issue. This check makes sense for title issue, but not for additional issues because we only display title of jbs issues for additional issues.

For example, if I have a pr whose title is "1: Test issue1", and then I use "/issue add 2" to associate another issue with this PR. Pr bot would add a hidden marker "" in a comment.
And I would see
"
Issue
 TEST-1: Test issue1
 TEST-2: Test issue2
"
in the pr body.

If I update the title of TEST-2 to "Test newIssue2" in JBS.

I would see
"
Issue
 TEST-1: Test issue1
 TEST-2: Test newIssue2( ⚠️ Title mismatch between PR and JBS.)
"
in the pr body because the jbs issue title is different from the issue title in the hidden marker.

The only way to fix it is removing the issue by "/issue remove 2" and then add it again.

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

Commit messages:
 - SKARA-2253

Changes: https://git.openjdk.org/skara/pull/1647/files
  Webrev: https://webrevs.openjdk.org/?repo=skara&pr=1647&range=00
  Issue: https://bugs.openjdk.org/browse/SKARA-2253
  Stats: 4 lines in 1 file changed: 3 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/skara/pull/1647.diff
  Fetch: git fetch https://git.openjdk.org/skara.git pull/1647/head:pull/1647

PR: https://git.openjdk.org/skara/pull/1647