Add ModelMesh support

[ckadner]

ModelMesh Integration:

• API Add modelmesh support #242
• Deployment Manifests
• UI

[ckadner]

@drewbutlerbb4 -- could you add some details above with respect to the changes you are planning to make, i.e. new API endpoints, deprecated/removed old APIs, etc. Thanks!

[ckadner]

@Tomcli -- do you remember if there was any outstanding work to be done on the ModelMesh integration for the API and for deployment manifests? What did we decide to do about UI integration?