Change bell identifier for unconfirmed fetch request bells

store-[id] is a pretty bad identifier, as there are other store bells with identifiers like store-new-[id] or store-arequest-[id].

I realized this as I wrote the script for deployment and I had to use a regular expression to distinguish these bells.

As bells for accepted requests are called store-arequest-[id] and bells for denied request are being called store-drequest-[id], I decided to rename the identifier for unconfirmed requests to store-urequest-[id]