### 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_
)
        response = aws_client.s3.list_bucket_intelligent_tiering_configurations(Bucket=bucket)
        snapshot.match("list_bucket_intelligent_tiering_configurations_2", response)
        # dele
        with pytest.raises(ClientError) as delete_err_1:
            aws_client.s3.delete_bucket_intelligent_tiering_configuration(
                Bucket="non-existing-bucket",
                Id=intelligent_tier_configuration["Id"],
            )
        snapshot.match(
            "delete_bucket_intelligent_tiering_configuration_err_1", delete_err_1.value.response
        )
        # dele
        with pytest.raises(ClientError) as delete_err_2:
            aws_client.s3.delete_bucket_intelligent_tiering_configuration(
                Bucket=bucket,
                Id="non-existing-id",
            )
        snapshot.match(
            "delete_bucket_intelligent_tiering_configuration_err_2", delete_err_2.value.response
        )
        # dele
        aws_client.s3.delete_bucket_intelligent_tiering_configuration(
            Bucket=bucket,
            Id=intelligent_tier_configuration["Id"],
        )
        response = aws_client.s3.list_bucket_intelligent_tiering_configurations(Bucket=bucket)
        snapshot.match("list_bucket_intelligent_tiering_configurations_3", response)
    @pytest.mark.aws_validated
    def test_s3_get__headers(self, aws_client, s3_create_bucket, snapshot):