Job submission code and API cleanup (#127)

* Refactor add jobs and make add_job api only be one job (instead of a list)

* Renamed to JobImportHandler and misc cleanup

* Dont bury exceptions in server proxy post_job

* Update code to create child jobs in a cleaner manner

src/distributed_job_manager.py

@@ -156,7 +156,7 @@ class DistributedJobManager:
         logger.debug(f"New job output path: {output_path}")
 
         # create & configure jobs
-        worker = EngineManager.create_worker(engine_name=new_job_attributes['engine'],
+        worker = EngineManager.create_worker(engine_name=new_job_attributes['engine_name'],
                                              input_path=loaded_project_local_path,
                                              output_path=output_path,
                                              engine_version=new_job_attributes.get('engine_version'),
@@ -358,7 +358,7 @@ class DistributedJobManager:
         logger.debug(f"Posting subjob with frames {subjob['start_frame']}-"
                      f"{subjob['end_frame']} to {server_hostname}")
         post_results = RenderServerProxy(server_hostname).post_job_to_server(
-            file_path=project_path, job_list=[subjob])
+            file_path=project_path, job_data=subjob)
         return post_results
 
     # --------------------------------------------