Prometheus Remote-Write receiver Alpha

[dashpole]

Component(s)

receiver/prometheusremotewrite

Describe the issue you're reporting

• Handle empty otel_scope_name and otel_scope_version
• Handle Timeseries samples
• Handle Counters
• Handle Histograms
• Handle Summaries (maybe too hard and could be left out for Alpha)
• Handle Created Timestamp
• Return number of samples and histograms ingested via response headers
• Handle multiple timeseries with same metric name+type+unit
• Handle target_info

[github-actions]

Pinging code owners for receiver/prometheusremotewrite: @dashpole @ArthurSens. See Adding Labels via Comments if you do not have permissions to add labels yourself. For example, comment '/label priority:p2 -needs-triaged' to set the priority and remove the needs-triaged label.