Implement Native Convolution Backward

[drahnr]

No description provided.

[subversive-owl]

These are the calls, right?

fn convolution_grad_filter(&self,
                               src_data: &SharedTensor<T>,
                               dest_diff: &SharedTensor<T>,
                               filter_diff: &mut SharedTensor<T>,
                               workspace: &mut SharedTensor<u8>,
                               config: &Self::CC)
                               -> Result<(), ::co::error::Error> {
        unimplemented!()
    }

    fn convolution_grad_data(&self,
                             filter: &SharedTensor<T>,
                             x_diff: &SharedTensor<T>,
                             result_diff: &mut SharedTensor<T>,
                             workspace: &mut SharedTensor<u8>,
                             config: &Self::CC)
                             -> Result<(), ::co::error::Error> {
        unimplemented!()
    }

[drahnr]

Yes, that is correct.