Test framework migration

[gurjotkaur20]

Improves #42 .

Description

Refactored the tests into Kubebuilder's framework using the gomega and ginkgo

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This PR has:

• been tested on a real K8S cluster to ensure creation of a brand new Druid cluster works.
• been tested for backward compatibility on a real K*S cluster by applying the changes introduced here on an existing Druid cluster. If there are any backward incompatible changes then they have been noted in the PR description.
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added documentation for new or modified features or behaviors.

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Key changed/added files in this PR

• controllers/druid/druid_controller_test.go
• controllers/druid/handler_test.go
• controllers/druid/suite_test.go
• controllers/druid/util_test.go
• controllers/druid/zookeeper_dep_mgmt_test.go
• go.mod
• go.sum

[AdheipSingh]

Approved to run workflow

[AdheipSingh]

Few minor changes. Rest LGTM !
Thanks @gurjotkaur20

[AdheipSingh]

cc @itamar-marom

[AdheipSingh]

@gurjotkaur20 please keep CRD definitions as it is, i am aware that the manifests get generated automatically. Will work on fixing that. For now, you can copy existing crd definitions.

[gurjotkaur20]

@gurjotkaur20 please keep CRD definitions as it is, i am aware that the manifests get generated automatically. Will work on fixing that. For now, you can copy existing crd definitions.

Okay. Reverted back the same.