Add draft and checks status to jj spr list output

[jennings]

Adds two new fields showing:

• If a PR is in draft status (pencil icon for draft, page for published)
• Whether all checks on a pull request have passed, any have failed, or
  if the result is still pending.

The output looks like this:

$ jj spr list
┌─────────┬─────────┬────────────────────────────────────────────────┐
│ Reviews │ Checks  │ Description                                    │
├─────────┼─────────┼────────────────────────────────────────────────┤
│ Pending │ Pending │ 📄 Display `list` output as a table            │
│         │         │ https://github.com/LucioFranco/jj-spr/pull/113 │
└─────────┴─────────┴────────────────────────────────────────────────┘