### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

In AWS, DescribeSubnet Response returns:
```
<?xml version="1.0" encoding="UTF-8"?>\n
    <Response>
        <Errors>
            <Error>
                <Code>InvalidSubnetID.NotFound</Code>
                <Message>The subnet ID \'test\' does not exist</Message>
            </Error>
        </Errors>
    <RequestID>f6d041c1-1c96-4720-af30-77745504e2ba</RequestID>
</Response>
```

whereas localstack returns:
```
<?xml version=\'1.0\' encoding=\'utf-8\'?>\n<Errors xmlns="http://ec2.amazonaws.com/doc/2016-11-15">
    <Error>
        <Code>InvalidSubnetID.NotFound</Code>
        <Message>aaThe subnet ID \'vpc-test\' does not exist</Message>
    </Error>
    <RequestID>EADJHWMM796CI5FT10XGFMGOXIPCBAHBWINMV0HR6SKBRODGCU5J</RequestID>
</Errors>

```

### Expected Behavior

It should return correct response structure. It causes terraform to complain.

### How are you starting LocalStack?

Custom (please describe below)

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    make start

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

     awslocal ec2 describe-subnets --subnet-ids vpc-test --debug


### Environment

```markdown
- OS: M1 MacOS
- LocalStack: 1.0.2.dev
```


### Anything else?

Probably `call_moto` function in `localstack/services/moto.py` is changing the error code structure.
message_type = "event"
        # set the headers
        headers = {":event-type": event_type, ":message-type": message_type}
        if error_message:
            headers[":error-message"] = error_message
        if error_code:
            headers[":error-code"] = error_code
        # construct headers
        header_section = b""
        for key, value in headers.items():
            header_name = key.encode(self.DEFAULT_ENCODING)
            header_value = to_bytes(value)
            header_section += pack("!B", len(header_name))
            header_section += header_name
            header_section += pack("!B", self.AWS_BINARY_DATA_TYPE_STRING)
            header_section += pack("!H", len(header_value))
            header_section += header_value
        # construct body
        if isinstance(content, str):
            payload = bytes(content, self.DEFAULT_ENCODING)
        else:
            payload = content
        # calculate lengths
        headers_length = len(he
        payload_length = len(payload)
        # construct message
        # - prelude
        result = pack("!I", payload_length + headers_length + 16)
        result += pack("!I", headers_length)
        # - prelude crc