Implement Interdomain.open_handle
Implement Interdomain.open_handle

Signed-off-by: John Else <37b74501daa612e48fea94f9846ed4ddeb6a8f07@citrix.com>

koushikcgit/xcp-rrdd,koushikcgit/xcp-rrdd,djs55/xcp-rrdd,johnelse/xcp-rrdd,johnelse/xcp-rrdd,djs55/xcp-rrdd,koushikcgit/xcp-rrdd