RFR: 713: Rename git/pr-approve to git-pr-review

[Guoxiong Li]

Hi all,

This patch changes the command `git pr approve` to `git pr review` and adds the option `type` to identify the review type `approve`, `request-changes` or `comment`.

I tested this patch in [PR1](https://github.com/openjdk/skara/pull/1) mistakenly. Apology for the wrong operation. And I can't find the right place to test the `git pr` command now.

Thanks for taking the time to review.

Best Regards,
-- Guoxiong

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Commit messages:
- 713: Rename git/pr-approve to git-pr-review

Changes: https://git.openjdk.java.net/skara/pull/1256/files
Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=1256&range=00
Issue: https://bugs.openjdk.java.net/browse/SKARA-713
Stats: 216 lines in 4 files changed: 124 ins; 86 del; 6 mod
Patch: https://git.openjdk.java.net/skara/pull/1256.diff
Fetch: git fetch https://git.openjdk.java.net/skara pull/1256/head:pull/1256

PR: https://git.openjdk.java.net/skara/pull/1256