### 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_
"""
        Moto tries to parse the TagSet and then iterate of it, not checking if it returned something
        Potential to be an easy upstream fix
        """
        try:
            tags: Dict[str, str] = fn(*args, **kwargs)
            for key in tags:
                tags[key] = tags[key] if tags[key] else ""
        except TypeError:
            tags = {}
        return tags
    @patch(moto_s3_responses.S3Response._cors_from_body)
    def _fix_parsing_cors_rules(fn, *args, **kwargs) -> List[Dict]:
        """
        Fix parsing of CORS Rules from moto, you can set empty origin in AWS. Replace None by an empty string
        """
        cors_rules = fn(*args, **kwargs)
        for rule in cors_rules:
            if rule["AllowedOrigin"] is None:
                rule["AllowedOrigin"] = ""
        return cors_rules
    @patch(moto_s3_responses.S3Response.is_delete_keys)
    def s3_response_is_delete_keys(fn, self):
        """
        Old provider had a fix for a ticket, concerning 'x-id' - there is no documentation on AWS about this, but it is probably still valid
        original comment: Temporary fix until moto supports x-id and DeleteObjects (#3931)
        """
        return get_safe(self.querystring, "$.x-id.0") == "DeleteObjects" or fn(self)
    @patch(moto_s3_responses.S3ResponseInstance.parse_bucket_name_from_url, pass_target=False)
    def parse_bucket_name_from_url(self, request, url):