Explore the use of Django Debug Toolbar

[FroggyFlox]

Now that we're on a more modern version of Django, we can explore the use of niceties and tools to help various aspects of the developer experience. In the Django world, the Django Debug Toolbar is a very popular and highly-recommended tool to provide such enhanced experience. As the project puts it:

The Django Debug Toolbar is a configurable set of panels that display various debug information about the current request/response and when clicked, display more details about the panel's content.

Behind this relatively simple description hides a rather powerful tool to catch and list a lot of information about DJango's operation when one visits a page. This is thus potentially very helpful in identifying slow and sub-optimal operations in Rockstor's backend operations. In particular, the ability to see all SQL queries done should be able to pinpoint unnecessary queries we may be doing and thus highlight bits we can speed up and simplify.

Main repository: https://github.com/django-commons/django-debug-toolbar
License: BSD-3-Clause (https://github.com/django-commons/django-debug-toolbar#BSD-3-Clause-1-ov-file)
Maintainers: Django-commons (https://github.com/django-commons)
Docs: https://django-debug-toolbar.readthedocs.io/en/stable/index.html

As mentioned above, this is a very very popular project that is currently very active.
Django 4.2 is the currently minimum version supported so we still fit.

I'm opening this issue so that we can explore in the open to what extent Django Debug Toolbar (DjDT) can help us and whether it is worth the setup. I'll also open a draft PR to better illustrate what would be needed to use it in Rockstor. Note that this is a developer tool only and should thus not be included in an rpm release.

[FroggyFlox]

With the configuration in FroggyFlox@3b9f8f2, we have:

• the toolbar showing up
• requests are caught and the toolbar is automatically updated with the latest AJAX call detected (thanks to UPDATE_ON_FETCH)
• all previous requests are available in the History panel. For instance, visiting the "Shares" page shows a lost of requests in the history panel:

Selecting the one related to the SharesListView (as selected in the screenshot above), and we can see that it made 23 SQL queries in 83 ms, with the details for each of these:

[FroggyFlox]

Further illustration with a known heavy page: Rock-on

This triggered 452 queries that took a little over 1 sec, but...

The page took a little over 6 sec to load, mostly loading the DOM (I think).