in_windows_exporter_metrics: Implement WMI based process metrics

[cosmo0920]

To monitor per process work loads, we need to implement process metrics on in_windows_exporter_metrics plugin.

Closes #7855

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Testing
Before we can approve your change; please submit the following in a comment:

• Example configuration file for the change

[SERVICE]
   flush_interval 10s
   log_level debug

[INPUT]
   Name windows_exporter_metrics
   scrape_interval 2s
   metrics process
   we.process.allow_process_regex /firefox|svchost/
   # we.process.deny_process_regex /firefox|svchost/

[OUTPUT]
   Name stdout

• Debug log output from testing the change

• Attached Valgrind output that shows no leaks or memory corruption was found

If this is a change to packaging of containers or native binaries then please confirm it works for all targets.

• Run local packaging test showing all targets (including any new ones) build.
• Set ok-package-test label to test for all targets (requires maintainer to do).

Documentation

• Documentation required for this feature
  in_windows_exporter_metrics: Add document for process metrics fluent-bit-docs#1182

Backporting

• Backport to latest stable release.

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Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

[edsiper]

cc: @lecaros docs