Issue #1056: improve reshaping in topo_view_to_design_mat

Addresses issue#1056 by correcting order of axes in the tensor transpose.

Round trip tests were already present in `test_dense_design_matrix.py`, so no new tests were added.
I thought about having the code document itself, and doing the following: 

```
batch_axes = (0, 1, 'c')
tensor_indices = [tensor_axes.index(axis) for axis in batch_axes]
batch_shape = np.array([V.shape[index] for index in tensor_indices])
```
but settled on the hard mapping for now.