Fix VerifySecret so it properly requeues when necessary

[abays]

We've come to realize three things recently:

1. Returning an error to the reconciler along with a RequeueAfter will cause the reconciler to abandon the explicit requeue and only consider the error [1].
2. The VerifySecret function in lib-common was returning an error along with a requeue, thus contributing to the problem listed in item 1. [2]
3. Also, the error VerifySecret was returning was not a "not found" error, but a generic k8s error -- so it wouldn't be properly handled by callers looking for a "not found" error. [3]

Now VerifySecret only returns a non-empty ctrl.Result{} if the Secret is missing, so let's handle that case in a separate if-clause. [4]

[1] openstack-k8s-operators/keystone-operator#459
[2] https://github.com/openstack-k8s-operators/lib-common/blob/ad3edb6e67ab738cfdbf4e2e78ac403784a08ab7/modules/common/secret/secret.go#L423-L425
[3] https://github.com/openstack-k8s-operators/lib-common/blob/ad3edb6e67ab738cfdbf4e2e78ac403784a08ab7/modules/common/secret/secret.go#L425
[4] https://github.com/openstack-k8s-operators/lib-common/blob/579da98fa7a62b70b43cdba92e82d6497afe8835/modules/common/secret/secret.go#L425-L427

[abays]

@abays: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:
Test name Commit Details Required Rerun command
ci/prow/glance-operator-build-deploy-kuttl 6e4343d link true /test glance-operator-build-deploy-kuttl

Full PR test history. Your PR dashboard.

Removing debug pod ...
error: unable to upgrade connection: container container-00 not found in pod oko-19-629pf-master-2-debug-wcjf7_openstack
make: *** [Makefile:551: crc_storage] Error 1
+ n=3
+ ((  n >= retries  ))
+ echo 'Failed to run '\''make crc_storage'\'' target. Aborting'
Failed to run 'make crc_storage' target. Aborting

/test glance-operator-build-deploy-kuttl

[fmount]

/lgtm

[openshift-ci]

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This pull-request has been approved by: abays, fmount

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[fmount]

thank you @abays for explaining the problem!