feat: add feature flag to clickhouse migration

[ANU7MADHAV]

Summary

The issue was that ClickHouse migrations were starting automatically when the server launched. To address this, I implemented a flag feature for conditional migrations. An environment variable, CLICKHOUSE_MIGRATION_ENABLED, was introduced with a default value of false. When set to false, migrations do not run; if changed to true, migrations will execute. This allows for an optimized, dynamic approach to managing migrations.

Related Issues / PR's

resolves #5678

Screenshots

NA

Affected Areas and Manually Tested Areas

---

[!IMPORTANT] Adds a feature flag to conditionally execute ClickHouse migrations based on an environment variable.

• Behavior:
  • Introduces CLICKHOUSE_MIGRATION_ENABLED environment variable to control ClickHouse migrations.
  • If false (default), migrations are skipped; if true, migrations are executed.
• Functions:
  • Adds IsClickhouseMigrationEnable() in constants.go to check the environment variable.
  • Updates ClickHouseMigrate() in migrate.go to accept a config parameter and conditionally execute migrations.
• Server Initialization:
  • Modifies NewServer() in server.go in both ee/query-service/app and pkg/query-service/app to use the new feature flag for migrations.

^{This description was created by for aae23725e0113e1ed7997ebc8ef2fdf97a9e551e. It will automatically update as commits are pushed.}

[welcome[bot]]

Welcome to the SigNoz community! Thank you for your first pull request and making this project better. 🤗

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}