Replace _solve_with_det by _can_solve_with_solution_with_det method

[fingolfin]

Nothing in any of our packages calls _solve_with_det anymore.

But in AA we find this:

# This can be removed once Nemo implements _can_solve_with_solution_with_det
# It's here now only because Nemo overloads it
function _solve_with_det(M::MatElem{T}, b::MatElem{T}) where {T <: RingElement}
   flag, r, p, piv, x, d = _can_solve_with_solution_with_det(M, b)
   !flag && error("System not solvable in _solve_with_det")
   return x, d
end