[MRM-1390] Add REST methods to search JCR store for generic metadata and properties

Add REST methods to search JCR store for generic metadata and properties

Added REST methods:

artifactsByProjectVersionMetadata/{key}/{value}
artifactsByMetadata/{key}/{value}
artifactsByProperty/{key}/{value}
searchArtifacts/{text}
searchArtifacts/{key}/{text}

In JCR implementation When searching into any property (key = nil) we can't do exact searchs

Some caveats with Cassandra implementation:
We can't search artifacts by any (wildcard) property, so searchArtifacts(text,...) just calls getArtifactsByMetadata
The exact parameter is ignored as we can't do non exact searches in Cassandra


Cassandra: rename Metadata Facet column 'key' to 'facetKey'
The column 'key' can't be queried in Cassandra
Probably because 'key' is reserved for the element key or a limitation in Hector

we started using a 3 digits version :-)