CP-3348: Xapi_blob.{send_blob,migrate_push}
CP-3348: Xapi_blob.{send_blob,migrate_push}

send_blob sends a blob to a remote pool via http handler. It requires the blob
object to already exist on the remote host.

migrate_push creates a blob object on the remote host, sends the blob to the
host, and then deletes the blob from the local host.

Signed-off-by: Mike McClurg <d5d39725aee3103039228164deec3c7acc6f60e3@citrix.com>

djs55/xcp-networkd,koushikcgit/xcp-networkd,sharady/xcp-networkd,simonjbeaumont/xcp-rrdd,johnelse/xcp-rrdd,djs55/xcp-networkd,djs55/squeezed,djs55/xcp-rrdd,simonjbeaumont/xcp-rrdd,djs55/xcp-rrdd,koushikcgit/xcp-rrdd,sharady/xcp-networkd,robhoes/squeezed,johnelse/xcp-rrdd,koushikcgit/xcp-networkd,koushikcgit/xcp-rrdd,koushikcgit/xcp-rrdd