AWS::Route53Resolver::ResolverEndpoint - Tag-update

## 1. Title
AWS::Route53Resolver::ResolverEndpoint-Tag

## 2. Scope of request
AWS::Route53Resolver::ResolverEndpoint-Tag-update can add tags but can not update existing tags

## 3. Expected behavior
Updating a Route53Resolver its tag in the CloudFormation stack should result in the new tag value.

## 4. Suggest specific test cases
Create Route53 resolver endpoint with tags, try to update the tag values with a stack update.

## 5. Helpful Links to speed up research and evaluation
/

## 6. Category (required) - Will help with tagging and be easier to find by other users to +1

Use the categories as displayed in the AWS Management Console (simplified):

1. Compute (EC2, ECS, EKS, Lambda...)
2. Storage (S3, EFS, Backup...)
3. DB (RDS, DynamoDB...)
**4. Networking & Content (VPC, Route53, API GW,...)**
5. Management (CloudTrail, Config...)
6. Machine Learning (SageMaker, ...)
7. Analytics (Athena, EMR, Glue,...)
8. Security (IAM, KMS...)
9. Integration (MQ, SQS, SNS,...)
10. Developer Tools (CodeStar, ...)
11. Other (IoT, Migration, Budgets...)

## 7. Any additional context (optional)