De-confusify histogram1 in .NET Meters API sample

It had implicit conflict with static label, which caused it to behave as unlabeled metric. Correct but potentially confusing because unlabeled metrics have special case publishing rules.

Added a custom label to make it act like a labeled metric.

Merge branch 'master' of https://github.com/prometheus-net/prometheus…

…-net

8.1.1

Fix bug in .NET Meters API adapter for UpDownCounter, which was incorrectly transformed to Prometheus metrics. prometheus-net#452 and prometheus-net#453

Clarify client HTTP request in progress tracking end

8.0.1

Disambiguate osme overloads

Default to EventKeywords.None

Merge branch 'master' of https://github.com/prometheus-net/prometheus…

…-net

* 5.0.2

- Bugfix: HttpClientMetrics under concurrent load with long-running requests were leading to broken response streams. prometheus-net#336

* 5.0.1

- Bugfix: PowersOfTenDividedBuckets did not work with >= 10 buckets due to overlap. Now skips overlapping region of generated series.