Instrument obsreport.Scraper

[moh-osman3]

This PR instruments obsreport.Scraper with otel go. This is a followup PR that is based on similar changes made for obsreport.Receiver: open-telemetry#6222

Link to tracking Issue: Part of open-telemetry#816

Testing:
Ran contrib collector with prometheusreceiver and hostmetricsreceiver and confirmed that new metrics show up. Tested both with feature gate disabled and enabled.

curl http://localhost:8888/metrics | tail -n 8 
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 14245    0 14245    0     0   869k      0 --:--:-- --:--:-- --:--:--  927k
# HELP otelcol_scraper_errored_metric_points Number of metric points that were unable to be scraped.
# TYPE otelcol_scraper_errored_metric_points counter
otelcol_scraper_errored_metric_points{receiver="hostmetrics",scraper="cpu",service_instance_id="020a1f19-6180-4de5-ae54-57cbd4ee9591",service_name="otelcontribcol",service_version="v0.62.0-60-g42049e14b"} 2
otelcol_scraper_errored_metric_points{receiver="hostmetrics",scraper="memory",service_instance_id="020a1f19-6180-4de5-ae54-57cbd4ee9591",service_name="otelcontribcol",service_version="v0.62.0-60-g42049e14b"} 0
# HELP otelcol_scraper_scraped_metric_points Number of metric points successfully scraped.
# TYPE otelcol_scraper_scraped_metric_points counter
otelcol_scraper_scraped_metric_points{receiver="hostmetrics",scraper="cpu",service_instance_id="020a1f19-6180-4de5-ae54-57cbd4ee9591",service_name="otelcontribcol",service_version="v0.62.0-60-g42049e14b"} 0
otelcol_scraper_scraped_metric_points{receiver="hostmetrics",scraper="memory",service_instance_id="020a1f19-6180-4de5-ae54-57cbd4ee9591",service_name="otelcontribcol",service_version="v0.62.0-60-g42049e14b"} 1