Add defaultDefaultClientScopes field to KeycloakRealm resource

[SmithJosh]

Related GH Issue

Closes https://github.com/keycloak/keycloak-operator/issues/534

Additional Information

Verification Steps

1. Run the operator
2. Create a KeycloakRealm resource with a client scope and add that scope to the defaultDefaultClientScopes field on the resource
3. Check that the client scope is listed in the default client scopes list in Keycloak and that, when adding a new client, the scope gets added to its default scopes list.

Checklist:

• [x] Automated Tests
• [ ] Documentation changes if necessary
• [ ] (If required) Discussed on Keycloak DEV