Use built-in function for combination reorder

[milesfrain]

[mschauer]

There is a test error, it seems this doesn't work for strings

Test Failed at /home/runner/work/Combinatorics.jl/Combinatorics.jl/test/combinations.jl:4
[39](https://github.com/JuliaMath/Combinatorics.jl/actions/runs/3440436304/jobs/5738901006#step:6:42)
  Expression: [combinations("abc", 3)...] == [['a', 'b', 'c']]
[40](https://github.com/JuliaMath/Combinatorics.jl/actions/runs/3440436304/jobs/5738901006#step:6:43)
   Evaluated: ["abc"] == Array{Char,1}[['a', 'b', 'c']]