Permit validation of multiple schemas

[science]

Current the system is able to validate only one incoming schema.

We will want to accept multiple schemas into LR. And we will want to partition validation into multiple communities, with accepted schemas being different in different communities.

[andersoncardoso]

Now each community can accept multiple schema 'types'. This is used for 'credential_registry', which has different schemas for 'organization' and 'credential'