This is a reland of 3c830222 with a fix.
Previous CL relied on summary data of CQ votes provided by Gerrit,
which apparently isn't always present in the way I expected.
This resulted in "git cl status" returning "lgtm" instead of "commit"
on Skia recipe roll CLs, which resulted in recipe roller abandoning CLs,
and creating new ones (there might be a bug in recipe roller, too).

The fix is to iterate over all votes on CQ label and finding the highest
score, and then deciding on the state.

Original change's description:
> git cl status: differentiate "dry-run" from generic "commit".
>
> CQ vote       now       before
>   +2       "commit"    "commit"
>   +1       "dry-run"   "commit"
>
> R=ehmaldonado
>
> Tested: manual "git cl status" run locally.
> Change-Id: I342a3ac0830a67bf0e722c737ef00460a0df4b98
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1548287
> Auto-Submit: Andrii Shyshkalov <tandrii@chromium.org>
> Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
> Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>

Change-Id: If9af5a2bf8f21d203b7a62740a27916eca0838ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1549640
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>