Deal with inf upper buond values

[paologallinaharbur]

Currently if the upper bound of a bucket is inf the bucket is discarded. I believe we should take care of such range in a better way to avoid losing values. Currently with a metric like:

# HELP powerdns_recursor_response_time_seconds Histogram of PowerDNS recursor response times in seconds.
# TYPE powerdns_recursor_response_time_seconds histogram
powerdns_recursor_response_time_seconds_bucket{le="0.001"} 0
powerdns_recursor_response_time_seconds_bucket{le="0.01"} 0
powerdns_recursor_response_time_seconds_bucket{le="0.1"} 0
powerdns_recursor_response_time_seconds_bucket{le="1"} 0
powerdns_recursor_response_time_seconds_bucket{le="+Inf"} 0

we would lose everything in the range 1<x<inf

infra-integrations-sdk/data/metric/metrics.go

Line 245 in 786cf26

// ignore +Inf buckets