dev.knotless.createPull

Writes a dev.knotless.pull record in the account logged in to this appview's web pages, as `knotless pull create` does: asking to merge a branch of this repository or a fork into one of its branches, both of which must exist. Refused, with the template, when the repository has one at the base (see dev.knotless.getTemplate) and the body follows none of it. Requires the session cookie the pages' login sets.