Add support for transforming metacards

[rzwiefel]

Add support for transforming metacards akin to the CatalogFramework methods transform

BinaryContent transform(
      Metacard metacard, String transformerId, Map<String, Serializable> requestProperties)
      throws CatalogTransformerException;

BinaryContent transform(
      SourceResponse response, String transformerId, Map<String, Serializable> requestProperties)
      throws CatalogTransformerException;

One thing to think about with this is how the input is provided over the remote interface. Does the caller need to supply the full data (aka metacard, sourceresponse, etc) and have it be reconstructed by us? Can we do some sort of value by reference where the caller can supply reference to metacards,etc that are desired and the querying can be done by us?