UnauthorizedOperation is not supported yet in error handling

### Describe the bug

If you block a region via AWS Control Tower, any operation (EBS, EC2, RDS) will return UnauthorizedOperation error.
This error can not be handled in a special way. Thats not good, but not a bug yet.
If you try to use `GetExceptionName` on the error, you get

` Unable to parse ExceptionName: UnauthorizedOperation`

as a result. And thats wrong.

```
// ...
const auto error = outcome.GetError();

// if(error.GetErrorType() == Aws::RDS::RDSErrors::UNAUTHORIZED_OPERATION) // -> not possible, since error does not exist
// {}

error.GetExceptionName() // -> returns "Unable to parse ExceptionName: UnauthorizedOperation"
```

### Expected Behavior

UnauthorizedOperation should be handled in all places where it can happen (i.e "core"?)

### Current Behavior

see "Describe the bug"

### Reproduction Steps

see "Describe the bug"

### Possible Solution

see "Describe the bug"

### Additional Information/Context

_No response_

### AWS CPP SDK version used

1.9.285

### Compiler and Version used

VS2022

### Operating System and version

Windows 11