Metadata coordination between discovery and application protocols

[markafoltz]

The existing spec checks for consistency between metadata obtained through DNS-SD (instance name) and CBOR (agent-info) and considers inconsistency a reason to flag the agent as not trustworthy.

https://www.w3.org/TR/openscreenprotocol/#instance-names

If we want to maintain this requirement, we need to rephrase this in a way that does not link DNS-SD and CBOR so closely.

[markafoltz]

From #344, @backkem wrote

It may be worth considering if part of the agent-info concerns are better handled on the 'network' side of the split. E.g.: it's hard to know what you're connecting to/authenticating without giving it a proper name. But this can be refined in iterations.

Agreed. agent-info also covers a lot of the application level concerns like the API capabilities of the agent and the locales for rendering presentations. One resolution would be to split it into multiple messages.