Add support for database migrations on business logic or db level changes

[samad-yar-khan]

Why do we need this ?

There are cases when a new column is added which is populated at the time of the sync. This change will not reflect in db existing data, but will be there in data synced after the version upgrade.

Example: We add a new url column in Incident Table like we did in this PR #245 . This uses some logic to populate url column in the sync itself but the existing rows will have null url. We should have a mechanism to do such database migrations as the logic can be more complex than a db query and re-syncing all data can be a pain.

Acceptance Criteria

• Build a service/system that can track data migrations that need to be performed on the existing data.
• It should be easy to create and setup the migrations for the developer.
• User should be able to run these migrations automatically or via some scripts on any version update.

Further Comments / References