Misc fixes for webinar demo

[annehaley]

This PR fixes some miscellaneous behavior that I discovered when preparing my demo for the webinar:

• The legend panel should only show that feature color props are being applied if those color props are present on some features.
• View states were not being fetched properly due to a bug in the GuardianFilter in access_control.py
• Fixed project selection behavior in project configuration page (it would reselect the previous project after creating a new project)
• Added a trailing slash to the API function for deleting a dataset
• Imported non-analytics tasks to ensure that they are registered by celery

[cloudflare-workers-and-pages]

Deploying geodatalytics with    Cloudflare Pages

Latest commit:	03671f5
Status:	✅  Deploy successful!
Preview URL:	https://378b3662.geodatalytics.pages.dev
Branch Preview URL:	https://demo-fixes.geodatalytics.pages.dev

View logs

[BryonLewis]

a few questions, I don't think any are blockers and could be implemented/updated if required.

[brianhelba]

1 question, 1 small code simplification

[brianhelba]

I haven't reviewed the Vue code, but the Python side makes sense.

[BryonLewis]

I think the changes made to the getColorPropsCoverage make it clearer what is happening, thanks.