### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

It seems that Sign operation ignores MessageType. 
As per AWS documentation the MessageType can be "DIGEST", that means the digest is already computed and just needs to be signed. 
https://docs.aws.amazon.com/kms/latest/APIReference/API_Sign.html

Localstack ignores this parameter:
https://github.com/localstack/localstack/blob/5fafd1b68f31f5948ec88b00a85966319c2ce8c3/localstack/services/kms/provider.py#L332

In GoLang the `Sign` interface takes the digest, not the raw message.
`Sign(rand io.Reader, digest []byte, opts crypto.SignerOpts)`
Therefore Sign/Verify operations in Go fail by using localstack.


### Expected Behavior

Use `MessageType` parameter and do not compute the digest when MessageType==`DIGEST`

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

Use Sign/Verify in GoLang

### Environment

```markdown
- OS: ubuntu
- LocalStack: latest
- GoLang 1.19
```


### Anything else?

_No response_
keys: Dict[str, KmsKey] = LocalAttribute(default=dict)
    
    
    
    #
    
    grants: Dict[str, KmsGrant] = LocalAttribute(default=dict)
    
    grant_names: Dict[str, str] = LocalAttribute(default=dict)
    
    grant_tokens: Dict[str, str] = LocalAttribute(default=dict)
    
    aliases: Dict[str, KmsAlias] = LocalAttribute(default=dict)
    
    imports: Dict[str, KeyImportState] = LocalAttribute(default=dict)
    
    
    #
    
    
    #
    
    
    
    def get_key(