Remove custom "save" functions from Javascript sketch

Throughout the sketches both @haschdl and @regisfrias make extensive use of the `save()` and/or `saveFrame()` functions.
In HTML5, one can simply right-click on a canvas and choose "Save image".

https://github.com/haschdl/dear-gen-code/blob/0ef3a463a364fdd0f81eeea4716e0532a60aaed2/helsinki/Week-07/sketch/sketch.js#L105-L122

I suggest we remove the "save" operations from sketches, unless it has a aesthetic reason. This would improve legibility of the code and reduce lines of code considerably.