libdm: preload propagates delayed resume

libdm: preload propagates delayed resume

Propagate delayed resume at least for preload case in a simple way.
Currently  PVMOVE depends on internal logic where 'mirror' with
corelog is 'possible' PVMOVE. In such case resume of 'created'
node is 'delayed'.

This is mostly an ugly internal hack - but for the moment being when we
add propagation for preload - it does work reasonable.

TODO: provide standard API and avoid this internal 'guessing'.