Adds `Serialize` and `Deserialize` implementation to `AlignedVec`

[aPere3]

This PR adds an implementation of the Serialize and Deserialize trait to AlignedVec. An implementation of PartialEq was also added since it was mandatory for the tests.

Those would be super useful for us. As we need to save large arrays of data in the Fourier domain.

I chose to hide the implementation behind a serialize feature, but I don't mind changing the structure.

[aPere3]

This is a gentle reminder. Would you consider merging such a PR ? That would be super useful for our work, and for the work of others I guess.