Changed the hidden element class name to a more generic one, so people can reuse it if they want to hide further elements in the future

Handling of the --hide-ui-dir-config flag and added multi-platform code for opening a folder

Adds icons on the first 3 tabs to directly open the corresponding images output directory

fixed some [send to..] buttons to work properly with all tabs

rework progressbar/preview to work with new gradio
remove unnecessary create style button
added link to alternative colab

SD upscale moved to scripts
Batch processing script removed
Batch processing added to main img2img and now works with scripts
img2img page UI reworked to use tabs

Random button sets seed to -1, reuse copies the seed from the last
generated image.