Ut for cache operators

[ramesh1220]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

kind task

What does this PR do / why do we need it: This adds UT for Cache Table Operators

Which issue(s) this PR fixes:

Fixes #405

Special notes for your reviewers:

[it-is-a-robot]

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[Nitin-Kashyap]

/sync

[it-is-a-robot]

@Nitin-Kashyap: sync pull request is restricted to collaborators

In response to [this](https://github.com/openlookeng/hetu-core/pull/406#issuecomment-1353051350): >/sync Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [opensourceways/test-infra](https://github.com/opensourceways/test-infra/issues/new?title=Prow%20issue:) repository.

[sraghunandan]

/sync

[sraghunandan]

/sync

[it-is-a-robot]

@sraghunandan: This pr has been synchronized to the Gitee Repository

In response to [this](https://github.com/openlookeng/hetu-core/pull/406#issuecomment-1354177078): >/sync Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [opensourceways/test-infra](https://github.com/opensourceways/test-infra/issues/new?title=Prow%20issue:) repository.