[Resources.Host] Rename host detector namespace

[matt-hensley]

Changes

Changes are following guidelines in #1610.

• Renames OpenTelemetry.ResourceDetectors.Host to OpenTelemetry.Resources.Host
• Makes detector internal
• Adds AddHostDetector extension method for ResourceBuilder

For significant contributions please make sure you have completed the following items:

• Appropriate CHANGELOG.md updated for non-trivial changes
• Design discussion issue #
• Changes in public API reviewed

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 75.45%. Comparing base (71655ce) to head (9314b8a).
Report is 260 commits behind head on main.

❗ Current head 9314b8a differs from pull request most recent head 9282e75

Please upload reports for the commit 9282e75 to get more accurate results.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1820      +/-   ##
==========================================
+ Coverage   73.91%   75.45%   +1.54%     
==========================================
  Files         267      300      +33     
  Lines        9615    11539    +1924     
==========================================
+ Hits         7107     8707    +1600     
- Misses       2508     2832     +324     

Flag	Coverage Δ
unittests-Exporter.Geneva	61.52% <ø> (?)
unittests-Exporter.OneCollector	89.72% <ø> (?)
unittests-Extensions	79.33% <ø> (?)
unittests-Instrumentation.AspNet	74.39% <ø> (?)
unittests-Instrumentation.AspNetCore	85.27% <ø> (?)
unittests-Instrumentation.EventCounters	76.36% <ø> (?)
unittests-Instrumentation.GrpcNetClient	78.78% <ø> (?)
unittests-Instrumentation.Http	81.79% <ø> (?)
unittests-Instrumentation.Owin	83.43% <ø> (?)
unittests-Instrumentation.Process	100.00% <ø> (?)
unittests-Instrumentation.Runtime	100.00% <ø> (?)
unittests-Instrumentation.SqlClient	90.90% <ø> (?)
unittests-Instrumentation.StackExchangeRedis	71.00% <ø> (?)
unittests-Instrumentation.Wcf	78.47% <ø> (?)
unittests-PersistentStorage	65.78% <ø> (?)
unittests-ResourceDetectors.Azure	81.53% <ø> (?)
unittests-Resources.Gcp	72.54% <ø> (?)
unittests-Resources.Host	52.87% <0.00%> (?)
unittests-Resources.Process	81.81% <ø> (?)
unittests-Resources.ProcessRuntime	72.91% <ø> (?)
unittests-Solution	80.17% <ø> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/OpenTelemetry.Resources.Host/HostDetector.cs	56.96% <ø> (ø)
...elemetry.Resources.Host/HostResourceEventSource.cs	16.66% <ø> (ø)
...ry.Resources.Host/HostResourceBuilderExtensions.cs	0.00% <0.00%> (ø)

... and 268 files with indirect coverage changes

[lachmatt]

LGTM