AWS::ElasticLoadBalancingV2::LoadBalancer - LoadBalancerAttributes are not reset on removal

This is a redirect of a bug report we've gotten here: https://github.com/aws/aws-cdk/issues/8976

Customer has created a NetworkLoadBalancer with the attribute:

```
load_balancing.cross_zone.enabled=true
```

Customer subsequently removes the attribute, but `cross_zone` is not actually disabled; instead, the current state is left as-is.

This means that the same template, when deployed, could lead to 2 different end states (depending on what was deployed before), which is anathema to the desired-state configuration system that CloudFormation intends to be.

## 3. Expected behavior

State of Load Balancer after deploying should depend only on the current template, not on previous states the Load Balancer has been in.

4. Networking & Content (VPC, Route53, API GW,...)