Update TensorImpl constructor to take the tensor  dimensions instead of the number of elements. Necessary for backend_opencv.

- [Syntax] Stimulis -> Stimuli and Stimuli -> Stimulus
- [#define] Use standard Aidge syntax format
- [Licence] add where missing
- [#include] add what is used and remove what is not
- [class] uniformize class member definition order
- [types] change size_t for std::size_t from <stddef> for uniformazation
- [types] change integer types for exact-width integers from <cstddint>
- Remove end-of-line spaces

[Merge] GraphView.hpp
[Doc] update documentation for Node.hpp and GraphView.hpp
[Upd] IOIndex_t from signed<uint16_t> to uint6_t. IONb_t is replaced by IOIndex_t because both types represent the same thing.
[Upd] Make many member-function arguments const for Node and GraphView to improve safety