sort a complex object that might contain other objects or/and arrays
The mock JSON used in tests are generated by https://onlinerandomtools.com/generate-random-json
Primitive (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures) will be returned unchanged.
Array and Object will be deep sorted by key - primitives first, objects following.
index.js contains the function. Though it is implemented as a node js module export (for easy testing), it easily could be transformed into client side function.