Split node tests into slow and fast tests

[koddsson]

I split up the node tests into "slow" and "fast" tests. Fast tests are tests that have a execution time of 25 milliseconds or less and slow tests execute in more than 25 milliseconds. They tests will timeout after 75ms. This change means that the fast test suite runs in roughly 1 second and the slow test suite in 2 minutes.

See developer-docs/testing-philosophy.md for more information on the whole philosophy of this change.

I still think there's a lot more we can do to make the tests faster and make the threshold even lower.

[changeset-bot[bot]]

⚠️ No Changeset found

Latest commit: e19ebe5e635cbf6003f0e80ef335e6ea6a6df1b2

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR