Add improved config/event output options to windows/perfmon metricset

[narph]

What does this PR do?

Works on improving the config, the new config is less repetitive and terser and will get a better overview of the configuration:

- module: windows
  metricsets:
  - perfmon
  period: 10s
  perfmon.group_measurements_by_instance: true
  perfmon.queries:
  - object: 'Process'
    instance: ["svchost*", "conhost*"]
    counters:
    - name: '% Processor Time'
      field: time.processor.pct
      format: "float"
    - name: 'Thread Count'
      field: thread_count
    - name: "IO Read Operations/sec"
// perfmon.counters can still be mapped and will return events but will be deprecated
  perfmon.counters:
  - instance_label: physical_disk.name
    measurement_label: physical_disk.write.per_sec
    query: '\PhysicalDisk(*)\Disk Writes/sec'

output wise, we offer some consistency with the other metricsets (example of event with the new format):

 "windows" : {
            "perfmon" : {
              "instance" : "svchost",
              "metrics" : {
                "time_processor_pct" : 0,
                "io_read_operations_per_sec" : 0,
                "thread_count" : 2
              },
              "object" : "Process"
            }
          },
          "event" : {
            "dataset" : "windows.perfmon",
            "module" : "windows",
            "duration" : 14153100
          }

POC contains the following:

• new configuration running along with the current configuration, if the user will populate the perfmon.queries list then events will have the new output, else the current one will still be possible. That comes with a deprecation message:

2020-04-10T14:03:57.670+0200	WARN	[cfgwarn]	perfmon/config.go:70	DEPRECATED: perfmon.counters configuration option is deprecated and will be remove in the future major version, we advise using the perfmon.queries configuration option instead Will be removed in version: 8.0
2020-04-10T14:04:00.407+0200	INFO	cfgfile/reload.go:224	Loading of config files completed.

• the new configuration will contain:
  • option to enter a label/field for the object value, if not entered it will be object
  • no option to enter a label/field for the instance value, it will be instance
  • option to enter a field/label for the counter value, if not entered, one will be generated based on the counter path
• ex. in the iis/website manifest.yml file on how the light metricsets will have to adapt to the setup

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Related issues

• Relates Move windows module / perfmon metricset to GA #16608, [Metricbeat] Grouping Windows Perfmon Metrics in Events #6584, Perfmon should generate unified static layout events for each performance monitor #12262

TO DO

• Add tests for the new setup as well
• Decide on default config/setup, deprecation process etc
• Rewrite manifest.yml for the iis/webserver light metricset as well

[elasticmachine]

Pinging @elastic/integrations (Team:Integrations)

[jsoriano]

This is looking good! I will take another look if there are changes for dedotting nested fields.

[jsoriano]

Align commented out code as before?

[jsoriano]

Thanks for the changes! Some additional suggestions on them.

[jsoriano]

Nit. Align the comment marks with the previous block:

Suggested change

	perfmon.queries:
	# - object: 'Process'
	# instance: ["*"]
	# counters:
	# - name: 'Disk Writes/sec'
	# field: physical_disk.write.per_sec
	# format: "float"
	# - name: "% Disk Write Time"
	perfmon.queries:
	#- object: 'Process'
	# instance: ["*"]
	# counters:
	# - name: 'Disk Writes/sec'
	# field: physical_disk.write.per_sec
	# format: "float"
	# - name: "% Disk Write Time"

[jsoriano]

Thanks! Great enhancement!