RBAC: Exception on unknown resource types

[Haarolean]

Set up:

1. config.yml with rbac and resource like "audit"
2. If the older image is used where the feature is not present, it will fail with the following exception:

Caused by: java.lang.NullPointerException: Cannot invoke "com.provectus.kafka.ui.model.rbac.Resource.ordinal()" because "this.resource" is null
	at com.provectus.kafka.ui.model.rbac.Permission.getAllActionValues(Permission.java:72)
	at com.provectus.kafka.ui.model.rbac.Permission.transform(Permission.java:67)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at com.provectus.kafka.ui.model.rbac.Role.validate(Role.java:15)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at com.provectus.kafka.ui.config.auth.RoleBasedAccessControlProperties.init(RoleBasedAccessControlProperties.java:16)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:425)
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:369)
	at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:193)
	... 53 common frames omitted