feat: add specialized fast implementations of `Polynomial + constant` and `Polynomial + Variable`#179

blegat merged 4 commits intoJuliaAlgebra:masterJuliaAlgebra/DynamicPolynomials.jl:masterfrom

AayushSabharwal:as/fast-opsAayushSabharwal/DynamicPolynomials.jl:as/fast-opsCopy head branch name to clipboard