Schema notification

Overview:

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These changes create a new Eventgrid topic (schemachangedtopic) for schema notification. Schema-Service is going to trigger a notification whenever there a create or update on the schema.

On the handler side, servicebus topic (servicebusschemachangedtopic) will also be created which would consume all of these events.

**Note: Patch endpoint of partition-service should be called to enable this eventgrid topic:

{
   "properties":{
      "eventgrid-schemachangedtopic-accesskey":{
         "sensitive":true,
         "value":"eventgrid-schemachangedtopic-accesskey"
      },
      "eventgrid-schemachangedtopic":{
         "sensitive":true,
         "value":"eventgrid-schemachangedtopic"
      }
   }
}

Infrastructure Submissions:

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• [YES] Have you added an explanation of what your changes do and why you'd like us to include them?
• [NO] I have updated the documentation accordingly.
• [NO] I have added tests to cover my changes.
• [YES] All new and existing tests passed.
• [YES] I have formatted the terraform code. (terraform fmt -recursive && go fmt ./...)

Current Behavior or Linked Issues

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Does this introduce a breaking change?

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• NO

Other information

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