Enhance metadata template editing

[michael-conway]

Enhance metadata template editing to move towards the current Consortium view of Metadata Templates.

• Evolve the metadata template reference implementation to use the 'irods-ext' database structure, bring up the new templates as separate tables via new migrations with eventual draw-down of the previous structures.

• Enhance metadata template services and editing per the agreed template feature set for the first iteration.

[michael-conway]

see attached mockups for some design proposals DC-templateDesigns_04092018.pdf