fix: Deletion resources related to subgroup

[zmotso]

Pull Request Template

Description

Problem:
If we delete the subgroup before deleting the resources that contain this subgroup
(Example: KeycloakRealmGroup.spec.subGroup/KeycloakRealmUser.spec.groups) deletion of KeycloakRealmGroup/KeycloakRealmUser blocks with an error. This happens because we are syncing KeycloakRealmUser/KeycloakRealmGroup before deletion, and syncing can't be processed without a subgroup.
Solution:
Moved deletion of KeycloakRealmUser/KeycloakRealmGroup before syncing. We don't need to sync objects that are marked for deletion.

Fixes #95

Type of change

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

How Has This Been Tested?

• Integration tests
• Manual testing

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• [ x 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 contain one commit. I squash my commits