RFR: 1807: Escape HTML in source code hosting provider's web UI as required

[Zhao Song]

To avoid format errors caused by '<' and '>' in PR comments, the PR bot should properly escape these characters before posting the comment on GitHub or GitLab.

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Commit messages:
 - SKARA-1807

Changes: https://git.openjdk.org/skara/pull/1465/files
 Webrev: https://webrevs.openjdk.org/?repo=skara&pr=1465&range=00
  Issue: https://bugs.openjdk.org/browse/SKARA-1807
  Stats: 28 lines in 6 files changed: 12 ins; 8 del; 8 mod
  Patch: https://git.openjdk.org/skara/pull/1465.diff
  Fetch: git fetch https://git.openjdk.org/skara pull/1465/head:pull/1465

PR: https://git.openjdk.org/skara/pull/1465