allow configuring scram arch for everything, fixes #3257

Allows to setup a default scram arch for all releases and then overrides for specific releases. This reduces the amount of configuration options as one specific release is only used from a single scram arch no matter in how many places in the Tier0 it is used.

Express and Repack CMSSW overrides are now not stored as overrides anymore but stored in the repack_config or express_config database tables. Also store the optional extra second step reco release for Express and store
scram arch for all choices separately. The reco_config table keeps its CMSSW version and scram arch columns.

The stream cmssw association table now only has the online CMSSW version, the override was removed as it
isn't needed anymore (override settings are applied at configuration time and the result of the override is stored).

Also get rid of all PromptSkim releated code.