Add Metrics YAML definitions for topology key

What does this MR do?

Add metric definition for topology key from Usage Ping

Add topology metric definition

  - Add topology metric definition
  - Add object_json_schema attribute with a
  link to json schema of the object inside
  topology key
  - Remove duration_s and failures separate
  definitions

I used Event Dictionary for descriptions

We use json-schema with description for each attribute

This will serve as a validation for data and documentation.

Example of data we have now in Usage Ping

{ ...
  "topology":
  {
    "nodes":
    [
      {
        "node_cpus":2,
        "node_services":
        [
          {"name":"prometheus", "process_count":1, "process_memory_rss":140824177}, 
          {"name":"node-exporter", "process_count":1, "process_memory_rss":12894815}, 
          {"name":"redis", "process_count":1, "process_memory_rss":11855294}, 
          {"name":"postgres", "process_count":1, "process_memory_rss":12669962}, 
          {"name":"workhorse", "process_count": 1, "process_memory_rss":23505663}, 
          {"name":"gitaly", "process_count":1, "process_memory_rss":32173454}
        ], 
        "node_uname_info": {"machine": "x86_64", "release": "3.16.0-9-amd64", "sysname": "Linux"}, 
        "node_cpu_utilization": 0.10634829100887147, 
        "node_memory_total_bytes": 6318419968, "node_memory_utilization": 0.5380808121780563}
      ], 
    "failures":
    [
      {"query_apdex":"empty_result"}, 
      {"service_uss":"empty_result"}, 
      {"service_pss":"empty_result"}, 
      {"service_workers":"empty_result"}
    ], 
    "duration_s": 0.13854128867387772, 
    "application_requests_per_hour":67
  }
....
}

Next steps

• Update #321811 (closed) for memory team to review the json schema for topology
• Create follow-up issue to validate usage ping data with this schema #325993 (closed)

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because _____.
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #323560 (closed)