feat(pulls): show PR URL in detail view (#1036)

Fixes #1035.

## Summary
- include the pull request URL in `tea pr <number>` detail output
- keep `tea pr create` output to one URL by relying on the shared detail renderer
- add a focused regression test

## Tests
- `go test ./modules/print`
- `go test ./...`

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Leon Müller <mueller4leon@gmail.com>
Reviewed-on: https://gitea.com/gitea/tea/pulls/1036
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: LeonM <206012+leonm@noreply.gitea.com>
Co-committed-by: LeonM <206012+leonm@noreply.gitea.com>

modules/task/pull_create.go

@@ -88,8 +88,6 @@ func CreatePull(requestCtx stdctx.Context, ctx *context.TeaContext, base, head s
 
 	print.PullDetails(pr, nil, nil)
 
-	fmt.Println(pr.HTMLURL)
-
 	return err
 }