E2E tests for labeling webhooks and selector

[tmshort]

There is a composed system to make the final correct response happen: one, or possibly two, webhooks -- a mutating webhook and possibly a validating webhook to enforce policy; operator-controller, catalogd. Because of this composed system, we should have add at least one e2e that confirms the happy path outcome works.

[tmshort]

This should be done in both catalogd and operator-controller.

Looks extremely straightforward to augment the existing e2e here: https://github.com/operator-framework/catalogd/blob/db28a52cd57400cbdac88f42e00bc2d4eabcff84/test/e2e/unpack_test.go#L64

Right after create succeeds, we can check that catalog var for the right label/value