Add additional inputs for BusinessSupportEditions

Adds priority, start and end date and facet inputs for BusinessSupportEdition.
govuk_content_models https://github.com/alphagov/govuk_content_models/commit/5bae378b017a45ad49d15f31b28c2da152d67db4
necessary for this to work so no version bump to content models gem in this commit.
Update content models dependency