VSD - configuration file - adding metrics filter to the comparison panel

Summary

Additional work split out of #385716 (closed). Once we're populating the Value Stream dashboard using a YAML configuration file, we want to add the ability to choose which metrics appear in the table.

Current metrics list in VSD.

This is the metrics list for the Next1-3 releases :

1. MR Throughput
2. Total Pipelines
3. Pipelines Success %

Configuration schema

Proposed schema of data attribute

data:
  # Will be supported once #385716 is merged
  type: metrics_comparison
  namespace: {GROUP_OR_PROJECT_NAMESPACE}

  # Exclude (filter) these metrics from the panel:
  exclude_metrics:
    - lead_time
    - cycle_time
    - new_issues
    - ...