PR close/reopen/merge confirmation titles were built from a fragment
template ("{{value0}} PR #{{value1}}?"), so locales could not reorder the
verb, and merge method labels came from English-only shared constants.
Add whole-sentence title keys per action and merge method plus translated
merge method labels in a renderer copy module, and route every PR surface
(item dialog, PR page, Tasks MergeCell, right-sidebar HostedReviewActions)
through it. Drop the English labels from the shared merge-method
presentation and remove the dead fragment keys from all locales.
Co-authored-by: Neil <4138956+nwparker@users.noreply.github.com>