### 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_
return int(i) if i else None
                begin, end = map(toint, rspec.split("-"))
                if begin is not None:  
                    end = last if end is None else min(end, last)
                elif end is not None:  
                    begin = length - min(end, length)
                    end = last
                else:
                    return 400, response_headers, ""
                if begin < 0 or end > last or begin > min(end, last):
                    raise s3_exceptions.InvalidRange(
                        actual_size=str(length), range_requested=range_header
                    )
                response_headers["content-range"] = f"bytes {begin}-{end}/{length}"
                requested_length = end - begin + 1
                content = get_range_generator_from_stream(
                    key_stream=key.value,
                    key_lock=key.lock,
                    start=begin,
                    requested_length=requested_length,
                )
                response_headers["content-length"] = requested_length
                return 206, response_headers, content
            body = get_generator_from_key(key_stream=key.value, key_lock=key.lock)
        return code, response_headers, body
def get_generator_from_key(