block data endpoints when syncing to not return result.

data endpoints which actually returns correct state of data when the indexer is fully synced could be blocked when we are still syncing like we do in offline mode.
So all the endpoints that provide blockchain data i.e. functional on the online mode should not return the data till the stage is live in the /network/status endpoint.
So all the endpoints that are not part of offline mode will need this check of stage.
/block
/account
/search endpoints

- Also the test cases has to be added for validation.