Move mocks to a separate package

[randmonkey]

Problem Statement

As we did in KIC: Kong/kubernetes-ingress-controller#6868, we want to move the mocks to a separate package inside /test
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Proposed Solution

• Move all the mock code to a package or multiple packaged inside /test
• Update the script to generate mock SDK to generate mock code in the dedicated package

Additional Information

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Acceptance Criteria

• All mocks are moved to a place inside /test