Add commands for reviews (#315)

add interactive `tea pr review`

it's amazingly simple

vendor gitea.com/noerw/unidiff-comments

add `tea pr lgtm|reject` shorthands

vendor slimmed down diff parser

review diff: default to true

if users want a shortcut, they can use lgtm or reject subcmds

`tea pr approve`: accept optional comment

Co-authored-by: Norwin Roosen <git@nroo.de>
Reviewed-on: https://gitea.com/gitea/tea/pulls/315
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: 6543 <6543@obermui.de>
Co-Authored-By: Norwin <noerw@noreply.gitea.io>
Co-Committed-By: Norwin <noerw@noreply.gitea.io>

cmd/pulls.go

@@ -34,6 +34,9 @@ var CmdPulls = cli.Command{
 		&pulls.CmdPullsCreate,
 		&pulls.CmdPullsClose,
 		&pulls.CmdPullsReopen,
+		&pulls.CmdPullsReview,
+		&pulls.CmdPullsApprove,
+		&pulls.CmdPullsReject,
 	},
 }