fix: Proceed to next group in list if SubGroups is an empty slice

[dougkirkley]

Pull Request Template

Description

During the getGroupByName function g.SubGroups can not be nil and return an empty slice, which the recursive getGroupByName function call will return early instead of proceeding to the next group in the original groups list. This occurs when there are two groups returned via the GetGroups API call, and one of them has a child group and another one does not.

Fixes #268

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Enhancement (non-breaking change which improves an existing feature or documentation)
• Breaking change (fix or feature that would cause existing functionality not to work as expected)

How Has This Been Tested?

Create a parent group and a child group from the issue

apiVersion: v1.edp.epam.com/v1
kind: KeycloakRealmGroup
metadata:
  name: system
  namespace: infra-system
spec:
  name: system
  realmRef:
    kind: KeycloakRealm
    name: infra
---
apiVersion: v1.edp.epam.com/v1
kind: KeycloakRealmGroup
metadata:
  name: system-no-children
  namespace: infra-system
spec:
  name: system_no_children
  realmRef:
    kind: KeycloakRealm
    name: infra
---
apiVersion: v1.edp.epam.com/v1
kind: KeycloakRealmGroup
metadata:
  name: child
  namespace: infra-system
spec:
  name: child
  realmRef:
    kind: KeycloakRealm
    name: infra
  parentGroup:
    name: system

Ensure there are no errors creating the CRs.

Checklist:

• I have performed a self-review of my code
• I have commented on my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Pull Request contains one commit. I squash my commits.