[Epic] Refactor ginkgo unit tests to go test

[perdasilva]

Description

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In discussion #168, we've decided to avoid using ginkgo for unit testing. We need to move our current ginkgo unit tests to go test.

Tasks

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• Update controllers package tests #190
• Update resolution package tests #191
• Update resolution/variablesources tests #192
• Update controllers/validators package tests #193
• Update resolution/entities package tests #194
• Update resolution/variables package tests #195
• Update e2e package tests #196
• Update resolution/util tests #197

[m1kola]

Probably worth leaving tests related to any of the following folders/files alone:

• internal/resolution/entities
• internal/resolution/entitysources
• internal/resolution/util/predicates
• internal/resolution/util/sort (most likely)
• cmd/resolutioncli/entity_source.go

We are going to remove entity sources soon-ish (#347) and we already have tests which does not use ginkgo in the package which is going to replace the above. See draft PR #393 for details.