Add regular_action_homomorphism function for a finite group G

[long-zm123]

regular_action_homomorphism(G::GAPGroup)

Return an isomorphism from finite $G$ onto the regular permutation representation of $G$.

Examples

julia> g = symmetric_group(5)
Symmetric group of degree 5

julia> hom = regular_action_homomorphism(g)
Group homomorphism
  from symmetric group of degree 5
  to permutation group of degree 120 and order 120

julia> number_of_moved_points(image(hom)[1]) == order(g)
true

[long-zm123]

Local testing is complete. Please review the code.