RFR: 1437: Fix the OpenJDK official role name and pluralization

[Guoxiong Li]

Hi all,

This patch mainly fixes the following message:

1. Remove the pluralization if these is 0 reviewer. `no reviews required` --> `no review required`
2. Fix the official role name. eg: `reviewer` --> `Reviewer`, `committers` --> `Committers`
3. Unify the comment and the progress message. ` (with 1 of role reviewers)` --> `(with at least 1 Reviewer)`
4. Fix the pluralization of the comment. ` (with 1 of role reviewers)` --> `(with at least 1 Reviewer)` Note the pluralization.

Thanks for taking the time to review.

Best Regards,
-- Guoxiong

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Commit messages:
 - SKARA-1437

Changes: https://git.openjdk.java.net/skara/pull/1319/files
 Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=1319&range=00
  Issue: https://bugs.openjdk.java.net/browse/SKARA-1437
  Stats: 98 lines in 4 files changed: 7 ins; 10 del; 81 mod
  Patch: https://git.openjdk.java.net/skara/pull/1319.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/1319/head:pull/1319

PR: https://git.openjdk.java.net/skara/pull/1319