Enable accepting short mac for node ids

 This fix makes possible to select nodes with short macs.
 e.g: fuel --env 1 node --node 6h:67,13:d3,7 --list
 Also added new method to tests, and expanded existing
 node tests to check for mac selects.

 Node data validation also implemented.

 Closes-Bug: #1273092

Change-Id: I1aaab3e24ef772d309c7832da0c55c583470893a
Merge "Enable accepting short mac for node ids"