Transforms are incompatible with functorch

[thelostscout]

When using the GlobalInternalCoordinateTransform together with functorch (more specifically jacrev), I encountered a lot of incompatibilities.
Some things I found that are incompatible:

1. calling requires_grad_(True) on tensors that already require gradients (haven't tried it for tensors without). E.g. in init_ics2xyz in ic_helper.py
2. calling torch.any, e.g. in dist_deriv in ic_helper.py
3. inplace arithmetics, e.g. in _rotmat3x3 in ic_helper.py

It seems like mainly ic_helper.py being the issue.