Management of the service-info endpoint

[mbaudis]

In the approval discussions for Refget v2 (currently underway) Emilio Righi @emiliorighi raised an interesting point:

A comment more related to the GA4GH workstream: the service-info endpoint should be removed by the API specs of the GA4GH products. The GA4GH should require API implementors to implement and manage the service-info enopoint instead.

For the long term this may be an interesting concept to follow: Move the service-info endpoint to documentation (i.e. document that & how those should be implemented) and have Beacon-specific information as a separate endpoint.

This is not a suggestion that it should be done like that but an invitation to discuss w/ some conclusion.

@jrambla @laurenfromont @costero-e ...