[COST-5195] - Prevent duplicate OCP cost model tasks

[lcouzens]

Jira Ticket

COST-5195

Description

This change will add a new worker cached args check to add and validate that no current cost model tasks have been queued matching the same args before queuing a new task.

Testing

1. Checkout Branch

2. Restart Koku with multiple workers

3. Load OCP data with a cost model

4. Add the following wait and log message to the update_cost_model_costs task.

    LOG.info(f"\n\n WAITING ON COST MODEL TASK \n\n")
    import time; time.sleep(100)
   

5. Generate new OCP data and post it via masu

6. Worker 1 should process the data then hang in the sleep (Simulating a task in-progress)

7. Generate/post new data again

8. See the second worker downloads/processes the report but this time logs the following. cost model update for range already queued, skipping new task.

Release Notes

• proposed release note

* [COST-5195](https://issues.redhat.com/browse/COST-5195) Prevent duplicate cost model update task being queued