feat: Add OpenShift exceptions

[doronkg]

What this PR does / why we need it

This PR excludes the default resources created in basic OpenShift installations.
In addition, I've moved the config load out of the processing loop in most resource types, to reduce excessive iterations.

PR Checklist

• This PR adds K8s exceptions (false positives)
• This PR adds new code
• This PR includes test for any new code

GitHub Issue

Closes #240

Notes for your reviewers

In pkg/kor/secrets.go, a new exception secret type was added - kubernetes.io/dockercfg, which is the OpenShift equivalent of kubernetes.io/dockerconfigjson.

Basic OpenShift installation comes with 60+ namespaces beginning with openshift- prefix, which doesn't include additional namespaces created by OpenShift operators or customized installations, that would also be created with that prefix.
For that case, I've excluded all openshift- namespaces in all relevant namespaced resource types, with the following pattern:

    {
      "Namespace": "openshift-.*",
      "ResourceName": ".*",
      "MatchRegex": true
    }

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 27.02703% with 27 lines in your changes missing coverage. Please review.

Project coverage is 41.30%. Comparing base (a2f3629) to head (92d3283).

Files	Patch %	Lines
pkg/kor/pdbs.go	25.00%	3 Missing and 3 partials ⚠️
pkg/kor/replicaset.go	25.00%	3 Missing and 3 partials ⚠️
pkg/kor/crds.go	0.00%	3 Missing ⚠️
pkg/kor/clusterroles.go	33.33%	1 Missing and 1 partial ⚠️
pkg/kor/daemonsets.go	33.33%	1 Missing and 1 partial ⚠️
pkg/kor/roles.go	33.33%	1 Missing and 1 partial ⚠️
pkg/kor/secrets.go	33.33%	1 Missing and 1 partial ⚠️
pkg/kor/services.go	33.33%	1 Missing and 1 partial ⚠️
pkg/kor/storageclasses.go	33.33%	1 Missing and 1 partial ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #311      +/-   ##
==========================================
- Coverage   41.38%   41.30%   -0.09%     
==========================================
  Files          61       61              
  Lines        3204     3220      +16     
==========================================
+ Hits         1326     1330       +4     
- Misses       1668     1674       +6     
- Partials      210      216       +6     

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[yonahd]

Couple small comments

[yonahd]

Lgtm