feat: add option to disable cluster rbac installation

[fadecore]

Problem

Currently it is not possible to install trust-manager in managed k8s clusters:

1. where it is not allowed to automatically install clusterroles.
2. where you are not allowed to create roles with resources that are currently not available inside the cluster, for example finalizers in non openshift clusters.

Solution

We need an option to install trust-manager without trying to create clusterroles during installation.
With an rbac switch it is possible to disable the installation of the clusterrole and clusterrolebinding.

[cert-manager-prow]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign wallrj for approval. For more information see the Kubernetes Code Review Process.

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

Needs approval from an approver in each of these files:

• OWNERS

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

[cert-manager-prow]

Hi @fadecore. Thanks for your PR.

I'm waiting for a cert-manager 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.