RFR: 574: git-info should use info from commit notifications

[Magnus Ihse Bursie]

git-info should use info from commit notifications to get the link to the review, not JBS (since not all PR have issues)

This required refactoring to move the hosted repo logic from cli/pr/Utils.java to where it can be accessed by all CLI tools. After some deliberating, I left a bunch of trivial wrappers in cli/pr/Utils.java -- otherwise this change would have touched *all* the files in cli/pr.

Testing: ad hoc testing of "git info" on some arbitrary Skara commits.

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Commit messages:
 - Use bot comment on forge for getReviewUrl instead of JBS
 - Extract getReviewUrl
 - Refactor so that `git info` can use hosted repository.

Changes: https://git.openjdk.java.net/skara/pull/1011/files
 Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=1011&range=00
  Issue: https://bugs.openjdk.java.net/browse/SKARA-574
  Stats: 338 lines in 5 files changed: 199 ins; 124 del; 15 mod
  Patch: https://git.openjdk.java.net/skara/pull/1011.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/1011/head:pull/1011

PR: https://git.openjdk.java.net/skara/pull/1011