(techdebt): refactor catalog controller unit tests

[everettraven]

Description:

• Removes the HTTPServer feature gate as there is no other logic for serving catalog contents which means this should now be the default.
• Refactors the Catalog controller unit tests to use pure Go testing + testify instead of Ginkgo.
• Removes the use of envtest for the Catalog controller tests and instead targets the reconcile() function for unit testing.
  • This does result in a lower test coverage score, but the removal of envtest results in a ~90% decrease in time spent running the unit tests (on my M2 Macbook Air main runs tests for the pkg/controllers/core package in ~6 seconds and this branch runs in ~.5 seconds)
  • A future tech debt item could be to investigate refactoring the Reconcile() function to make it easier to test the logic without using envtest.
• Removes the tests for the SetupWithManager() function as it wasn't really providing any value

Motivation

• partial resolution of Refactor unit tests to not use Ginkgo #153 (there was discussion that it probably makes sense to tackle one package at a time to keep PRs manageable)

[codecov]

Codecov Report

Attention: 23 lines in your changes are missing coverage. Please review.

Comparison is base (9f3ba06) 49.72% compared to head (f3788f7) 46.15%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #196      +/-   ##
==========================================
- Coverage   49.72%   46.15%   -3.58%     
==========================================
  Files           6        6              
  Lines         366      364       -2     
==========================================
- Hits          182      168      -14     
- Misses        163      177      +14     
+ Partials       21       19       -2     

Files	Coverage Δ
pkg/controllers/core/catalog_controller.go	77.22% <100.00%> (-12.97%)	⬇️
cmd/manager/main.go	10.00% <0.00%> (+0.07%)	⬆️

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[stevekuznetsov]

Why was it valid to lose this?

[everettraven]

This was necessary when the reconcile() function would call helper functions, passing the fs.FS that was returned from the source.Unpacker.Unpack() call, that would create the Package, BundleMetadata, and CatalogMetadata CRs. Since this was happening as part of the reconciliation loop we had to ensure our MockSource was returning an fs.FS with a proper set of FBC files. Since we no longer do that and the logic for storing catalog contents is now abstracted + mocked for these unit tests we can provide an empty fs.FS from our mock source.

This should instead be used when testing the storage logic directly and has already been duplicated over there previously:

catalogd/pkg/storage/localdir_test.go

Lines 155 to 184 in 9f3ba06

	const testBundleTemplate = `---
	image: %s
	name: %s
	schema: olm.bundle
	package: %s
	relatedImages:
	- name: %s
	image: %s
	properties:
	- type: olm.bundle.object
	value:
	data: %s
	- type: some.other
	value:
	data: arbitrary-info
	`
	const testPackageTemplate = `---
	defaultChannel: %s
	name: %s
	schema: olm.package
	`
	const testChannelTemplate = `---
	schema: olm.channel
	package: %s
	name: %s
	entries:
	- name: %s
	`