replace jimp and sharp with own functions

[nnmrts]

both, especially jimp, have their downfalls when it comes to performance and modernity, also sharp use libvips, so it's not pure javascript

• jimp

  • discuss if we should definitely remove it
  • identify the parts we currently use
  • remove it from dependencies

• sharp

  • discuss if we should definitely remove it
  • identify the parts we currently use
  • remove it from dependencies