pimd: Add additional IGMP stats (generic/group specific queries sent)

pimd: Add additional IGMP stats (generic/group specific queries sent)

```
exit1-debian-11# sh ip igmp statistics
IGMP statistics
Interface            : global
V1 query             : 0
V2 query             : 0
V3 query             : 6
V2 leave             : 0
V1 report            : 0
V2 report            : 0
V3 report            : 14
mtrace response      : 0
mtrace request       : 0
unsupported          : 0
joins failed         : 0
joins sent           : 16
general queries sent : 6
group queries sent   : 4
total groups         : 5
total source groups  : 1
exit1-debian-11# sh ip igmp statistics json
{
  "global":{
    "name":"global",
    "queryV1":0,
    "queryV2":0,
    "queryV3":6,
    "leaveV2":0,
    "reportV1":0,
    "reportV2":0,
    "reportV3":18,
    "mtraceResponse":0,
    "mtraceRequest":0,
    "unsupported":0,
    "totalGroups":5,
    "totalSourceGroups":1,
    "joinsFailed":0,
    "joinsSent":16,
    "generalQueriesSent":6,
    "groupQueriesSent":4
  }
}
```

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>