[Regression] Execution API endpoint with wait=true no longer returns flow outputs

[razuro]

Feature description

Propose the Execution API of: http://localhost:8080/api/v1/executions/{namespace}/{flow_id}?wait=true

to have the same output as: http://localhost:8080/api/v1/executions/{execution_id}

Without the query params wait=true, we'll need to do two API calls;

1. to trigger execution
2. to get execution result

It's only natural to have the final output result for http://localhost:8080/api/v1/executions/{namespace}/{flow_id}?wait=true as it waits for the process to complete, so we can have the final result