Update metric service to get aggregated metrics

[munishchouhan]

closes #469
This PR will add the following

1. This PR will add a function in counterProvider to get all matching data data using hscan
2. This will add a method in metric service to get the count per org and total count
3. Add new model for the response

When no date or ord is provided then metrics endpoint will return the above

[munishchouhan]

Tested successfully in local

[munishchouhan]

Working on only getting the /metrics/o records from redis

[munishchouhan]

Working on only getting the /metrics/o records from redis

Hscan uses glob pattern, so we need to get all the records in metrics/o/ and then filter out the relevant ones

[munishchouhan]

@pditommaso its ready for review

[pditommaso]

Got an error trying this

» curl -u foo:bar http://localhost:9090/v1alpha2/metrics/fusion/pulls
{"message":"Cannot invoke \"java.util.Map.entrySet()\" because \"self\" is null - Error ID: 375c044c6d5f"}

[munishchouhan]

Got an error trying this

» curl -u foo:bar http://localhost:9090/v1alpha2/metrics/fusion/pulls
{"message":"Cannot invoke \"java.util.Map.entrySet()\" because \"self\" is null - Error ID: 375c044c6d5f"}

fixed

[pditommaso]

Ok, nice