Fake user support + puppeteer test

[bkrmendy]

Description

This PR adds a puppeteer test that navigates to a project, logs in with a fake user, creates a comment, and resolves it.

To run the tests, run pnpm run comments-test from /path/to/utopia/puppeteer-tests.

Details

Making the flow above work needed the following changes:

Supporting fake users

With this PR, the server supports an allowlisted fake user (Alice), which is special-cased during the login flow. If the ?fakeUser=alice query param is in the URL at load time, the server will authenticate with a pre-created user.

So far, the server has only supported fake users locally. With this change, the prod environment will support fake users too.

Support setting feature flags via URL params

If the name of a feature flag is added to the query params set to 'true' (such as Commenting=true), that feature flag will be turned on.

Next steps (after merging this PR)

• update the test to always open the same project on pizza

[github-actions]

Try me

[relativeci]

Job #9717: Bundle Size — 62.2MiB (~+0.01%).

00a1870(current) vs df0030c master#9709(baseline)

Warning

Bundle contains 66 duplicate packages – View duplicate packages

Bundle metrics   2 changes 1 regression

	Current Job #9717	Baseline Job #9709
Initial JS	45.4MiB(~+0.01%)	45.4MiB
Initial CSS	0B	0B
Cache Invalidation	19.86%	11.6%
Chunks	26	26
Assets	30	30
Modules	4361	4361
Duplicate Modules	470	470
Duplicate Code	30.75%	30.75%
Packages	462	462
Duplicate Packages	65	65

Bundle size by type   1 change 1 regression

	Current Job #9717	Baseline Job #9709
JS	62.18MiB (~+0.01%)	62.18MiB
HTML	11.54KiB	11.54KiB

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View job #9717 report View tests/pizza-fake-user branch activity

[github-actions]

Performance test results:

[Rheeseyb]

To run the tests as part of the PR process, you'll need to add a job to https://github.com/concrete-utopia/utopia/blob/master/.github/workflows/pull-requests.yml. I can help with that if you need me to. I'd suggest doing that in a follow up PR though, as it requires the server-side changes, which wouldn't be deployed until after this has been merged.