Variable length for splitStringsChunkLength

[piranna]

Is your feature request related to a problem? Please describe.

splitStringsChunkLength split the strings in a fixed length, that can lead to some tips about how to recompose the original strings. I propose to split them on random lengths.

Describe the solution you'd like

Allow to define a function instead of a number is the most general solution. Alternatively we can use an array, although still not sure if it should have two values defining a range, or being a list of the desired lengths. That later one can help with base64 encoding, because if strings are split in multiples of 3, there are no tailing = characters that can provide a tip they are end of base64 encoded strings instead of random data that can be at any position.