Include jscodeshift for JS upgrades

[alexander-schranz]

For JS changes there exist also the possibilities to create transformers via jscodeshift. I think it would be great to include this also for sulu-rector to update also JS to newer sulu versions.

It is not target to run jscodeshift via rector binary but it would be great to have the jscodeshift transformers inside this repository so a Sulu upgrade just requires the sulu-rector package.