postgres 14: EXTRACT returns a numeric, which is converted to a strin…

[haraldschilly]

Description

• see issue extract and postgresql 14 #5824
• the conversion in postgres-blobs.coffee is not necessary, I don't see why. Must be related to rethinkdb.
• the other client/server data serializations make sense. I've thought about this, and to me it makes sense to convert to a float (pg calls it "double precision") like before.

tests:

• un-archiving a series of patches works fine
• listings on the share server show timestamps when last edited
• stopping idle projects … I just manually set the last edited field to something in the past and project stopped as expected

Checklist:

• Testing instructions are provided, if not obvious
• Release instructions are provided, if not obvious

[williamstein]

Very nice code!