Simplification of radicals

[ChrisRackauckas]

MWE:

using Symbolics
@variables y
simplify.([(1//2)*√(4y), (-1//2)*√(4y)])
simplify_fractions.([(1//2)*√(4y), (-1//2)*√(4y)])

julia> simplify.([(1//2)*√(4y), (-1//2)*√(4y)])
2-element Vector{Num}:
  (1//2)*sqrt(4y)
 (-1//2)*sqrt(4y)

julia> simplify_fractions.([(1//2)*√(4y), (-1//2)*√(4y)])
2-element Vector{Num}:
  (1//2)*sqrt(4y)
 (-1//2)*sqrt(4y)

I think step one is to make this √(4)*√(y) * 1//2, and then have it learn it can simplify perfect squares.