### 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_
import datetime
import io
import json
import logging
import os
import re
import struct
import uuid
from collections import namedtuple
from dataclasses import dataclass
from hashlib import sha256
from typing import Dict, List
from cryptography.exceptions import InvalidSignature
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives import serialization as crypto_serialization
from cryptography.hazmat.primitives.asymmetric import ec, padding, rsa
from localstack.aws.accounts import get_aws_account_id
from localstack.aws.api import CommonServiceException
from localstack.aws.api.kms import (
    CreateAliasRequest,
    CreateGrantRequest,
    CreateKeyRequest,
    DisabledException,
    EncryptionContextType,