feat: Added option to provide custom queues

[fproldan]

What type of a PR is this?

• Changes to Existing Features
• New Feature Submissions
• Bug Fix
• Breaking Change (include change in API behaviours, etc.)

---

This PR adds the option to configure a new settings in common_site_config.json that allows creating custom workers besides the defaults hardcoded in supervisor.conf.

The new setting is named "workers" and should be in this format:

"workers": {
    "<queue_name>": {
        "timeout": <timeout>, 
        "background_workers": <workers>,
    }   
 }

Example:

"workers": {
    "myqueue": {
        "timeout": 5000, 
        "background_workers": 4,
    }   
 }

The background_workers param is optional, if not set the general background_workers will be used.

[gavindsouza]

Thanks for your contribution 💯

I think the config key workers would be more accurate instead of custom_queues, since they are actually just named workers not queues.

[fproldan]

@gavindsouza changes made!

[gavindsouza]

LGTM, can you raise a PR that adds docs to frappe/frappe_docs too?

[gavindsouza]

@fproldan We missed adding this to the Procfile 😅 . Can you raise a PR for the same?

[fproldan]

@gavindsouza done!