support NWC and NCW format for 1Dconvolution export and forwardDims

(previously !446 (closed))

Context

I've got another incoming Merge Request to implement Conv1D operator CPP export : aidge_export_cpp!53 (merged)

For that I needed node_export.py and Conv.cpp to support tensors of dimension 3 (format NCW or NWC)

Modified files

• node_export.py getters implemented for channels / height(==1) / width / batch size for a given tensor of dim 3 (format NCW or NWC)
• Conv.cpp conditions for dimension forwarding for format NWC

TODO

• DONE