### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

CopyObject API does not check precondition headers such as `x-amz-copy-source-if-modified-since`. Instead it seems to always copy the object.

### Expected Behavior

The API should return a 412 response with content similar to:

```
<Error><Code>PreconditionFailed</Code><Message>At least one of the pre-conditions you specified did not hold</Message><Condition>x-amz-copy-source-If-Modified-Since</Condition><RequestId>14HR9PXJRG5B1GR5</RequestId><HostId>HztBs2jYea1fzzPWo1JWy33NQJqo1S1IsK62rkbnVEI04PnGNCi8sPVrichGQxH3FQwLA2RIyF4=</HostId></Error>
```

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

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

    docker run localstack/localstack

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

```
aws s3  --profile localstack --endpoint-url http://s3.localhost.localstack.cloud:4566 \
  ls s3://net-amazon-s3-test/Makefile.am
2023-01-25 10:47:40        537 Makefile.am

aws s3api copy-object --copy-source net-amazon-s3-test/Makefile.am --key Makefile.am.2 \
  --bucket net-amazon-s3-test2 --profile localstack --endpoint-url http://s3.localhost.localstack.cloud:4566 \
  --copy-source-if-modified-since "Wed, 25 Jan 2023 16:16:27 GMT"
{
    "CopyObjectResult": {
        "ETag": "\"46ada9d1fe8f8a311ff4504c226e061c\"",
        "LastModified": "2023-01-25T16:18:43+00:00"
    }
}
```

### Environment

```markdown
- OS: penguin
- LocalStack: latest
```


### Anything else?

_No response_
"""Change casing of Last-Modified and other headers to be picked by the parser"""
        status_code, resp_headers, key_value = fn(self, *args, **kwargs)
        for low_case_header in [
            "last-modified",
            "content-type",
            "content-length",
            "content-range",
            "content-encoding",
            "content-language",
            "content-disposition",
            "cache-control",
        ]:
            if header_value := resp_headers.pop(low_case_header, None):
                header_name = capitalize_header_name_from_snake_case(low_case_header)
                resp_headers[header_name] = header_value
        
        
        bucket_key_enabled = "x-amz-server-side-encryption-bucket-key-enabled"
        if val := resp_headers.get(bucket_key_enabled, ""):
            resp_headers[bucket_key_enabled] = str(val).lower()
        return status_code, resp_headers, key_value
    @patch(moto_s3_responses.S3Response._bucket_response_head)
    def _fix_bucket_response_head(fn, self, bucket_name, *args, **kwargs):
        code, headers, body = fn(self, bucket_name, *args, **kwargs)
        bucket = self.backend.get_bucket(bucket_name)
        headers["x-amz-bucket-region"] = bucket.region_name
        headers["content-type"] = "application/xml"
        return code, headers, body
    @patch(moto_s3_responses.S3Response._key_response_get)
    def _fix_key_response_get(fn, *args, **kwargs):