[O11y][CockroachDB] Lens Migration

[rajvi-patel-22]

Manually migrate CockroachDB visualizations to lens in current Kibana version 8.4.0 itself.

Preparation of data for testing

• Use sample_event.json / setup live instance using docker / mock data using mock server to populate dashboards

Migration stats

CockroachDB Dashboards	Before Migration		After Migration
	Lens	Visualization	Lens	Visualization
[CockroachDB Metrics] Overview	0	7	7	0
	0	7	7	0

Dashboard : [CockroachDB Metrics] Overview

• Migrate 7 visualization to the lens.
  • [O11y][CockroachDB] Migrate visualizations to lens in Kibana 8.4.0 #5688

Verification and Validation

• Verification of functionality remains the same after migration in Kibana
• Verification of data count of after-migrated visualization with before-migrated visualization in Kibana
• Verification of Dashboard are not distorted in supported Kibana version (8.4.0)

[rajvi-patel-22]

PR is approved and merged, hence closing this issue: #5688