sc2repo: refactor configuration file syntax

[pdowler]

The sc2repo.properties config file has a really old format that is very inconsistent with the (improved) practices we adopted in storage inventory (specifically thinking of baldur and raven where one creates an “entry” and then a set of properties for it on separate lines.

I don’t think it would be much work to implement a new config style like
ca.nrc.cadc.caom2.repo.entry = FOO
FOO.basePublisherID = ??
FOO.readOnlyGroup = ??
FOO.readWriteGroup = ??
FOO.operatorGroup = ??
FOO.staffGroup = ??
FOO.proposalGroup = true

Technically, only basePublisherID and readWriteGroup are required for a functional repo service.

In the sc2repo impl, there is only one database and we currently have only one maintained SQLGenerator impl, so the other config items are not really configurable separately (the pool and database are in the context.xml and confdigurable props go into catalina.properties).