introduce labels for resources to be backed up

[wkloucek]

Description

Introduces a new option to set labels on resources that must be backed up.

Related Issue

• Compare to https://doc.owncloud.com/ocis/5.0/maintenance/b-r/backup_considerations.html
• see also OCSRE-92

Motivation and Context

Currently there is no other way to inject labels to specific resources

How Has This Been Tested?

• installing the develoment example deployment with following changes:

diff --git a/deployments/development-install/helmfile.yaml b/deployments/development-install/helmfile.yaml
index 6edf79a..0bdd3b3 100644
--- a/deployments/development-install/helmfile.yaml
+++ b/deployments/development-install/helmfile.yaml
@@ -14,6 +14,17 @@ releases:
               hosts:
                 - ocis.kube.owncloud.test

+      - backup:
+          configMapLabels:
+            backup.test/include: "true"
+            backup.test/configmap: "test"
+          secretLabels:
+            backup.test/include: "true"
+            backup.test/secret: "test"
+          pvcLabels:
+            backup.test/include: "true"
+            backup.test/pvc: "test"
+
       - logging:
           level: debug

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Technical debt
• [ ] Tests only (no source changes)

Checklist:

• [x] Code changes
• [ ] Unit tests added
• [ ] Acceptance tests added
• [ ] Documentation generated (make docs) and committed
• [ ] Documentation ticket raised:
• [ ] Documentation PR created:

[wkloucek]

@d7oc this should answer your questions (see also the description)

• Compare to https://doc.owncloud.com/ocis/5.0/maintenance/b-r/backup_considerations.html

Could we please split cleanups from the basic topic of the PRs.

I can do it

EDIT: done