[occm] consider private network name when node contains IPs from other private...

[occm] consider private network name when node contains IPs from other private networks - release-1.18 (#1053)

* OCCM: consider network names, when specified
* Move v1 helper functions into openstack_instances.go
* [occm] Address detection logic fixes

Signed-off-by: Andrey Klimentyev <andrey.klimentyev@flant.com>

* Typo fix

* Move LB related helpers into occm package

* Added comment

Co-authored-by: Andrey Klimentyev <andrey.klimentyev@flant.com>

Co-authored-by: kayrus <kayrus@users.noreply.github.com>
Co-authored-by: Andrey Klimentyev <andrey.klimentyev@flant.com>