Upstream Resnext3d from classivision

[jdsgomes]

🚀 The feature

• Upstream resnext3d from classyvision
• Replace conv3d + norm + activation blocks with the new Conv3dNormAct block
• Run tests and make sure the performance is in line with the original implementation

Motivation, pitch

This effort will contribute to the [RFC] Batteries Included - Phase 2 initiative

Alternatives

No response

Additional context

No response

cc @datumbox

[jdsgomes]

Closing this ticket because the classyvision implementation is not canonical and because we are focusing our efforts now on adding newer architectures such has MViT.