catalogd web api unit test misc fixes

[grokspawn]

with the new API, there are a couple of things we missed during review around the unit tests that we need to take care of

1. response body format for all catalogd web endpoints is jsonlines, and we used to have a test that enforced this was consistent. It was removed and we need to restore it so that if our "happy accident" that created JSONL-by-default encoding here ever changes, we can adjust as soon as the dependency bumps
2. rename http_precoditions_check.go --> http_preconditions_check.go
3. remove suite_test.go since there are no longer any ginkgo tests in the suite.

[azych]

/assign