Fixes #8538 - Fixed ISC DHCP states and duplicities

Our ISC DHCP parser was not respecting binding states "free" vs "active" and
it was reading free (released) leases as active. Also, with longer lease
times it was loading multiple leases as duplicities. Both was causing
conflicts in Foreman.

(cherry picked from commit a7c8c34d2221bee133f602c35d4f25bf0bcec353)