Rename ImportClusterResourceService to OneshotClusterResourceImporter

[saza-ku]

What type of PR is this?

/area simulator
/kind cleanup

What this PR does / why we need it:

If we add the syncing service (#327), it has two features to import resources of a real cluster, one-shot importing and continuous syncing.
So the current naming of ImportClusterResouceService would be confusing.

This PR renames ImportClusterResourceService to OneshotClusterResourceImporter. This will avoid the confusion.

Which issue(s) this PR fixes:

Part of #327

Special notes for your reviewer:

We should also rename mock_clusterresourceimporter, but this is generated by gomock so we need to replace golang/mock with uber-go/mock (#363). This PR once leaves it.

/label tide/merge-method-squash

[k8s-ci-robot]

Hi @saza-ku. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[utam0k]

/lgtm from my eyes

The code itself looks good. But I'd like to know @sanposhiho's opinion.

[sanposhiho]

/ok-to-test

[sanposhiho]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ordovicia, sanposhiho, saza-ku

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [sanposhiho]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment