Consolidate and add tests for tutorials

[braingram]

As came up during docs review we have a few types of "tutorials":

• https://github.com/asdf-format/asdf-adass2024
• https://github.com/asdf-format/asdf-website/tree/main/asdf_website/tutorials
• https://github.com/asdf-format/scipy2022tutorial/

It may be beneficial to consolidate these to:

• make them easier to test/maintain/upgrade
• make them easier to discover

[melanieclarke]

I also noticed this one, which looks like it is no longer active: https://github.com/asdf-format/tutorials

[braingram]

Closing as tutorials were updated and tests added in asdf-format/tutorials#21