[Resources.Process] Rename process detector namespace

[matt-hensley]

Changes

Changes are following guidelines in #1610.

• Renames OpenTelemetry.ResourceDetectors.Process to OpenTelemetry.Resources.Process
• Makes detector internal
• Adds AddProcessDetector 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 76.26%. Comparing base (71655ce) to head (cd77963).
Report is 239 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1717      +/-   ##
==========================================
+ Coverage   73.91%   76.26%   +2.34%     
==========================================
  Files         267      298      +31     
  Lines        9615    11622    +2007     
==========================================
+ Hits         7107     8863    +1756     
- Misses       2508     2759     +251     

Flag	Coverage Δ
unittests-Exporter.Geneva	64.39% <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-ResourceDetectors.Host	54.11% <ø> (?)
unittests-ResourceDetectors.ProcessRuntime	76.08% <ø> (?)
unittests-Resources.Gcp	72.54% <ø> (?)
unittests-Resources.Process	81.81% <0.00%> (?)
unittests-Solution	80.17% <ø> (?)

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

Files	Coverage Δ
...OpenTelemetry.Resources.Process/ProcessDetector.cs	100.00% <ø> (ø)
...ources.Process/ProcessResourceBuilderExtensions.cs	0.00% <0.00%> (ø)

... and 281 files with indirect coverage changes

[Kielek]

Hi @matt-hensley, I have merged changes related to creating bugfixes/features to this branch.

Couple of comments added to specific files.
What is more important we need changelog entry containing two thiings.

1. Package rename
2. How to migrate from old construction to the new one.