chore: add additional info for host metrics onboarding

[srikanthccv]

Summary

Part of #5373

Helps in onboarding related changes

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Important

Add functions to check host metrics and Kubernetes agent metrics in HostsRepo, update HostListResponse, and introduce GetCountOfThings() in ClickHouseReader.

• Behavior:
  • Add DidSendHostMetricsData() and IsSendingK8SAgentMetrics() to HostsRepo in hosts.go to check for host metrics data and Kubernetes agent metrics.
  • Update GetHostList() in hosts.go to include results from the above functions in the response.
• Functions:
  • Add GetCountOfThings() to ClickHouseReader in reader.go to count data entries for a given query.
• Interfaces:
  • Add GetCountOfThings() to Reader interface in interface.go.
• Constants:
  • Add SIGNOZ_TIMESERIES_V4_TABLENAME to constants.go.
• Models:
  • Update HostListResponse in infra.go to include SentAnyHostMetricsData and IsSendingK8SAgentMetrics.

^{This description was created by for 7f2b22f. It will automatically update as commits are pushed.}

[ellipsis-dev]

❌ Changes requested. Reviewed everything up to 7f2b22f in 3 minutes and 18 seconds

More details

• Looked at 151 lines of code in 5 files
• Skipped 0 files when reviewing.
• Skipped posting 1 drafted comments based on config settings.

1. pkg/query-service/app/clickhouseReader/reader.go:3389

• Draft comment:
  Ensure the query string is sanitized or validated to prevent SQL injection vulnerabilities.
• Reason this comment was not posted:
  Comment did not seem useful.

Workflow ID: wflow_KfXogSEVeXcWa3qr

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