iprep: extends cidr support

Implements new API to expand the IP reputation
to netblocks with CIDR notation

A new object 'srepCIDRTree' is kept in the DetectionEngineCtx,
which contains two tree (one for ipv4 and one for ipv6)
where the reputation values are stored.
detect-iprep: extends cidr

Adds new API to check if an IP address is belong
to a netblock and gets the value.
iprep: add unit tests for cidr

Implements unit tests to test the new API