chore: Colocate Discover/Performance utils (#38248)
An outcome from Frontend TSC, we're co-locating
tests to make them more discoverable, have them as
references to learn about the module/components
and better visibility into what is being tested. [This](https://github.com/getsentry/sentry/pull/37618/files)
change should ensure tests under the test/ folder
as well as colocated tests get run in CI as we move
files over in batches.
(PR 4/n)
Previous PRs:
https://github.com/getsentry/sentry/pull/38234
https://github.com/getsentry/sentry/pull/38235
https://github.com/getsentry/sentry/pull/38240
Shruthi