Fix various minor issues (#545)

* Add absolute URL to power tests

* Update to target Python 3.10

* Return user to current page when clicking 'mark reviewed'

* Add units to power test record detail and form

I'm a bad scientist (coz I'm an engineer)

* Allow a higher value in PSSC fields

* Default venue to event venue in EC/PT

* Fix population of initial venue values for EC/PT

* Add link to create power test from EC detail

* Do not set power plan field to required on RA

"This might be a problem if the risk assessment is being done by one person and the power plan by another."

* Default power MIC to MIC

* Implement some suggestions from the Doctor

* Prevent checking in to cancelled events and dry hires

Will close #539

* Exclude dry hires from H&S overview list

* Add "ex VAT" tooltips to asset purchase price and replacement cost

* Automagically clear and focus ID field when audit modal closes

Closes #533

* Delete unused things

* Allow two decimal places in cable length, show training item IDs in selectpicker

Will close #540

* Fix #524 500 Error when viewing qualification list for items nobody is qualified in

* Update README.md

* Add a guard against nulls in recent changes

Maybe fixes #537 I'm unable to replicate locally

* Turn down verbosity of CI tests, fix tests, potential speedup

* Squash migration

* Add encoding to open

* Update to v3 upload-artifact

Resolves a deprecation warning

training/tests/test_interaction.py

@@ -44,7 +44,7 @@ def test_add_qualification(logged_in_browser, live_server, trainee, supervisor,
     page.submit()
     assert page.success
     qualification = models.TrainingItemQualification.objects.get(trainee=trainee, item=training_item)
-    assert qualification.supervisor.pk == supervisor.pk
+    assert qualification.supervisor_id == supervisor.pk
     assert qualification.date == date
     assert qualification.notes == "A note"
     assert qualification.depth == models.TrainingItemQualification.STARTED