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

まず、issueで言及されているGetExceptionName呼び出しとエラー処理の中核部分から始め、次にEBS、EC2、RDSの各操作がUnauthorizedOperationをどのように返すかを比較します。完了の条件は、UnauthorizedOperationがparse-errorメッセージなしで認識され、issueで発生し得るとされているすべての箇所で一貫して処理できることです。

索引モデルが issue の本文から書いたものです。