AWS::CE::AnomalyMonitor should return friendly error on unsupported region

### Name of the resource

AWS::CE::AnomalyMonitor

### Resource name

_No response_

### Description

When we try to create AWS::CE resources on region other than us-east-1 we get error Template format error: Unrecognized resource types: [AWS::CE::AnomalySubscription, AWS::CE::AnomalyMonitor]

Please enhance the error to instead say that these resources must be created on us-east-1 instead.

### Other Details

similar issue #1020

The issue names AWS::CE::AnomalyMonitor and AWS::CE::AnomalySubscription and links similar issue #1020, but identifies no source file, test, or entry point. Start by reviewing issue #1020 and the repository's handling of unsupported regional resource types. Done means unsupported regions produce a friendly message directing users to us-east-1.

Written by the indexing model from the issue text.