Rework flow breed (#2926)

Right now, there is, in essence, a static mapping between flow protocols
and flow breeds.
Make it dynamic: allow to have different flows, with the same
classification but differents breeds. This is the same logic that we
already have for categories....

Preliminary work to support breed in category lists.

API change from the app POV: to get the flow breed don't use anymore
`ndpi_get_proto_breed()`, but access directly `struct ndpi_proto->breed`

The functions `ndpi_domain_classify_*()` and
`ndpi_get_host_domain_suffix()` now have a `u_int32_t` parameter as
`class_id` (instead of `u_int_16_t`), with the following logic:
```
class_id = (breed << 16) | category
```
instead of the old:
```
class_id = category
```
Please note that this change is back-compatible: if you are not
interested into breeds, you don't need to update the application code.

tests/cfgs/default/result/gnutella.pcap.out

@@ -39,11 +39,11 @@ WSD	41	39162	4
 LLMNR	10	770	6
 NAT-PMP	4	176	4
 
+Unrated                        298 19232         86           
 Safe                            21 4395          1            
 Acceptable                     184 57460         38           
 Potentially_Dangerous          3374 495188        634          
 Dangerous                        5 1215          1            
-Unrated                        298 19232         86           
 
 Unspecified                    298 19232         86           
 Media                           21 10027         2