[ETL] Optimize schemaMigration to be updated only if there are changes

[himeshr]

Need

As part of every org/orgGroup ETL run, we invoke SchemaMetadata "Migrate" operation, which performs update of the SchemaMetadata for each table/ column / index metadata of the org/orgGroup, every single time.

Due to this, there exists following undesired effects

• Migrate operation costs almost 30 seconds of run-time for each org.
• Applies needless load on Avni database due to no change update operations

Recommendation (needs further analysis and prioritzation)

• Compute diffs that include Create / Update as well as Delete changes in schemaMetadata
• Only if there are changes, then perform the following snippet of code

public class SchemaMigrationService {
     public Organisation migrate(Organisation organisation) {

....

        schemaMetadataRepository.applyChanges(changes);
        organisation.applyNewSchema(newSchemaMetadata);
        schemaMetadataRepository.save(organisation.getSchemaMetadata());
....
    }
}