The RPC generator doesn't support returning list of object, this patch does
the work manually.

  * daemon/remote.c:
    Implement the server side handler remoteDispatchConnectListAllStoragePools

  * src/remote/remote_driver.c:
    Add remote driver handler remoteConnectListAllStoragePools.

  * src/remote/remote_protocol.x:
    New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_STORAGE_POOLS and
    structs to represent the args and ret for it.

  * src/remote_protocol-structs: Likewise.