[BUG] Use UCP_AM_FLAG_WHOLE_MSG and UCP_AM_FLAG_PERSISTENT_DATA for receive handlers

[abellina]

For receive handlers that want to call amData.receive after the UCX callback completes (i.e. rndv/buffers) we must pass UCP_AM_FLAG_PERSISTENT_DATA in setAmRecvHandler. The flags argument to this function is getting added in JUCX 1.11-rc1, and we don't have an official jar published with it yet (other than SNAPSHOT). We also should set UCP_AM_FLAG_WHOLE_MSG to prevent fragment-sized multiple callbacks for eager messages.

The plan is to move to JUCX 1.11-SNAPSHOT and test it works, then PR that. There should be a 1.11-rc1 jar published (officially) next week, and we should be able to move to that, irrespective of when the non-RC 1.11 jar is published. Note: there's a 1.11.0 JAR published currently, but it was published by mistake => so I'd imagine the official one would be 1.11.0.1 or 1.11.1.

[abellina]

This, unfortunately, is blocked until UCX 1.11 native is released as well. UCX 1.10.1 is not able to work with GPU buffers, so we can't move to Active Messages yet for all buffers. UCX 1.11 RC1 was tagged so we are going towards that version.