The try-out page's checks and request body get tests under the
package's node runner: the repo check, a row's checks in their order,
a shared name, and the open-a-PR gate (repo, then each row in order,
then a shared name, with no PR number). Also the row a request sends,
and the row a loaded rule becomes.
Refs #5259
The runtime list was exported but only its type was used, so the type is
now written out. The form's pure logic (draft, checks, request body,
change detection) gets tests under node's built-in runner, run by the
existing swarm-ui check.
