### 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_
fn,
        self,
        bucket_name: str,
        query: dict[str, Any],
        key_name: str,
        headers: dict[str, Any],
        *args,
        **kwargs,
    ) -> TYPE_RESPONSE:
        """Return an iterator if the content returned is a `SpooledTemporaryFile`, which indicates that the return
        value is from `GetObject`. We transform this stream into an iterator, to control how much we return"""
        code, response_headers, body = fn(
            self, bucket_name, query, key_name, headers, *args, **kwargs
        )
        if isinstance(body, SpooledTemporaryFile):
            
            version_id = query.get("versionId", [None])[0]
            key = self.backend.get_object(bucket_name, key_name, version_id=version_id)
            
            
            
            if code == 200 and (range_header := headers.get("range", "")) != "":
                length = key.size
                last = length - 1
                _, rspec = range_header.split("=")
                if "," in rspec:
                    raise NotImplementedError("Multiple range specifiers not supported")
                def toint(i: Any) -> Optional[int]: