Add transform to service api on Mars

[datadavev]

After discussion on slack, initially decided on adding transform to:

/thing/{identifier}?format=full|original|core

Where:

full = record as present in the backing database
original = the record as retrieved from the original source
core = record transformed to the iSamples core model

the default value if not provided is original.

[datadavev]

oops - duplicate