This PR fulfills the requirements of #9069 by:
- Adding a golangci-lint directive (forbidigo) to disallow all fmt.Errorf usages.
- Replacing existing fmt.Errorf instances with structured errors from github.com/SigNoz/signoz/pkg/errors for consistent error classification and lint compliance.
- Verified lint and build integrity.
* chore(savedview): refactor into module and handler
* chore(rule): move telemetry inside telemetry
* chore(apdex): refactor apdex and delete dao
* chore(dashboard): create a dashboard module
* chore(ee): get rid of the init nonesense
* chore(dashboard): fix err and apierror confusion
* chore: address comments