RFR: 224: Add --no-draft flag to `git pr list`

[Erik Helin]

Hi all,

please review this patch that adds the flag `--no-draft` to `git pr list`.

Thanks,
Erik

## Testing
- [x] Manual testing of `git pr list`

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Commits:
 - 39c6c7c1: skara-224

Changes: https://git.openjdk.java.net/skara/pull/349/files
 Webrev: https://webrevs.openjdk.java.net/skara/349/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/SKARA-224
  Stats: 10 lines in 1 file changed: 9 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/349.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/349/head:pull/349

PR: https://git.openjdk.java.net/skara/pull/349