DAOS: ability to drop rxm connections on the server side

[Alexander Oganezov]

We on the DAOS project would like to have an ability to drop internal rxm peer connection from the server side.
Ideally some API like fi_av_remove() would trigger dropping of the internal connection with the peer being removed.

This API might allow DAOS then to scale on verbs/tcp;rxm beyond current scales that hit connection limits, by, for example, monitoring and dropping LRU av entries

[Sean Hefty]

See #8190. This adds an environment variable to the libfabric core to request cleanup of all underlying resources associated with an AV entry (including connections). Some quick verification was done using the tcp provider and fabtests.

A better option is to add a flag to the AV to request this behavior. That will need to be a separate change. Use of that will require code changes at the upper layer. Even if #8190 works for you, keep this request open to track the API update.