Schematize nuanced immutability (conditional resource replacement, downtime, etc.)

[rjlohan]

Currently, the CloudFormation resource specification and the documentation do not distinguish the difference between an update operation which fully replaces a resource (including data loss) from those updates which cause some other kind of downtime (e.g a server or database reboot).

The documentation maps both of these concepts to 'Update requires: some interruption' and the resource spec maps only the fully immutable replacement operation, as does the schema currently.

We could include a schema property to signal that a property may cause downtime without data loss as a distinguishing concept.

[PatMyron]

@rjlohan trying to assemble a list of likely stateful resource types here to help prevent data loss:
https://github.com/aws-cloudformation/cfn-python-lint/blob/f476b226753a6df494091f392d78990ef93517ef/src/cfnlint/rules/resources/UpdateReplacePolicyDeletionPolicyOnStatefulResourceTypes.py#L22-L44

[PatMyron]

In addition to this problem with createOnlyProperties being more nuanced than being expressable in just a boolean, the same problem applies to readOnlyProperties and writeOnlyProperties as well
https://twitter.com/InesParnisari/status/1327040431138299904