Django-lightweight-queue

- Adds support for Django 4 in the Debug Web backend (thanks itsthejoker)
- Moves from using `imp` to `importlib` to load "extra" settings
- Adds logging of jobs timeouts for better observability
- **potentially breaking** Drops support for Python 3.5

Adds missing typing-extensions dependency.

Thanks itsthejoker for reporting.

Fixes a couple of deprecation warnings:
- no longer exports a `default_app_config` above Django 3.2
- moves from using `imp` to `importlib` in concert with Django's import helpers for task discovery

Makes the background `CronScheduler` thread resilient to errors which happen during its `tick` function. Previously these errors would bubble to the top of the thread, causing it to exit. As the master process doesn't monitor the cron thread this would result in no cron tasks being enqueued until the master was restarted.

Introduces commands to pause and resume queues with deadlines. Currently this is supported by the Redis backends.
While a queue is paused no jobs will be processed; if you want jobs to be dropped while the queue is paused you will need to clear the queue manually before it resumes.

This resale also updates the linters used to their latest versions and consequently now requires at least Python 3.6.1 (up from 3.6).

Clarify that insertion ordering is preserved when bulk enqueueing.