Split base tests from end to end, regenerate screenshots

[rly]

Refs:

• Try using node installed from conda #902 (comment)
• Update puppeteer, re-enable mac CI, split e2e CI #910 (comment)

[rly]

I changed npm run coverage:app to no longer run end-to-end tests. To run the end-to-end tests, use npm run coverage:tutorial. I also moved puppeteer.ts into the e2e test folder and made puppeteer a dev dependency. Lastly, I regenerated the screenshots and changed the dandiset for test upload to be a new one that I own, and I updated the DANDI_STAGING_API_KEY secret for this repo to my staging dandiset key.

[rly]

@CodyCBakerPhD feel free to suggest alternate names and organization. Just thought I would try to do this while it was fresh in my mind. Also the screenshots needed updating.

[CodyCBakerPhD]

@rly Looks great! Thanks a bunch