Centralize credential handling

My thinking is that this may reduce the cognitive overhead for
developers writing new test suites.

This also allows us to perform different setup steps (like ensuring the
editor is visible when authenticated).

test/utils/constants.ts

@@ -1,3 +1,2 @@
 export const PASSWORD = "e45432jklfdsab"
-export const storageState = JSON.parse(process.env.STORAGE || "{}")
 export const workspaceDir = "workspaces"