VTOrc Cleanup: Remove KV stores

[GuptaManan100]

Description

Orchestrator supports key-value stores for primary discovery which is documented here at https://github.com/openark/orchestrator/blob/master/docs/kv.md. Vitess has topo-server for this and VTOrc does not need a separate kv-store. This PR removes the VTOrc specific code to kv-stores and all its uses.

Related Issue(s)

• RFC: Orchestrator as a native Vitess component #6612

Checklist

• "Backport me!" label has been added if this change should be backported
• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

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