DeletionPolicy / UpdateReplacePolicy resource type coverage

[Resource types that support snapshots](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-deletionpolicy.html)
[Resource types that support snapshots](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-updatereplacepolicy.html)

**Missing Snapshot support for:**
[`AWS::DynamoDB::Table`](https://docs.aws.amazon.com/cli/latest/reference/dynamodb/)
[`AWS::DocDB::DBCluster`](https://docs.aws.amazon.com/cli/latest/reference/docdb/)
[`AWS::FSx::FileSystem`](https://docs.aws.amazon.com/cli/latest/reference/fsx/)
[`AWS::EMR::Cluster`](https://docs.aws.amazon.com/cli/latest/reference/emr/)
[`AWS::QLDB::Ledger`](https://docs.aws.amazon.com/cli/latest/reference/qldb/)

**Missing Delete support for:**
[AWS::S3::Bucket](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-s3-bucket.html) ([`aws s3 rb s3://$BUCKET --force`](https://docs.aws.amazon.com/cli/latest/reference/s3/rb.html)) (might timeout)
[AWS::ECR::Repository](https://stackoverflow.com/questions/49175834/how-to-force-delete-an-aws-ecr-with-cloudformation)

---

I'd also like a new policy for all resource types that doesn't allow removal from the stack and stops forward progress of the stack update

All current options, `Delete` / `Retain` / `Snapshot`, mean old resources can no longer be managed through CloudFormation if [resource import doesn't support their resource type yet](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/resource-import-supported-resources.html). This new policy would allow users to more easily prevent this compared with needing to evaluate [change sets](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-changesets.html) or write [IAM stack policies](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/protect-stack-resources.html)

Start with the linked CloudFormation DeletionPolicy and UpdateReplacePolicy documentation, then compare the listed resource types with the resource import support list. Confirm which snapshot and delete behaviors are missing, and define the proposed policy that prevents resource removal while stopping stack-update progress. Done means the supported coverage and the new policy behavior are specified and implemented.

Written by the indexing model from the issue text.