Adds function for dimension computation

[RafaelDavidMohr]

As requested per @rprebet this would add a function to compute the dimension of a polynomial ideal (if we want such "high level" functions in AlgebraicSolving.jl).

[mohabsafey]

I think it is nice to have it in AlgebraicSolving.jl. Many thanks. A few comments/questions:
(1) could you rename other-algorithms.jl to dimension.jl and (2) wouldn't it be benefitial to have a function computing the Hilbert series so that we could get the dimension and the degree of the ideal (if you have time for this?)?

[rprebet]

Thanks @RafaelDavidMohr !
@mohabsafey : We also discussed Hilbert series computation, I agree this would indeed be very helpful. However, since this will require more work/time, we thought this could be done in a separate PR.

[RafaelDavidMohr]

I think it is nice to have it in AlgebraicSolving.jl. Many thanks. A few comments/questions: (1) could you rename other-algorithms.jl to dimension.jl and (2) wouldn't it be benefitial to have a function computing the Hilbert series so that we could get the dimension and the degree of the ideal (if you have time for this?)?

Files are renamed.