Implement `smartAlign`

[opatiny]

[opatiny]

We have the issues that the images can have different sizes in stacks, so we have to be able to align images that don't entirely overlap, which is different from the align function already implemented.

Remark: once we are able to align images that don't overlap entirely, the algorithm should also handle the case where they do overlap. Hence this new algorithm should replace the old align -> see how to entirely remove the old algo?