New loading screen design

[Segergren]

Here is a Preview
Works good for now but needs improvement.

[lulzsun]

It looks 10x better than what we have right now, but I think this implementation needs more changes before it is ready to merge.

Here are some things I would suggest doing:

• Instead of creating another pictureBox for this, reuse pictureBox1
  • the reason you want to use pictureBox1 is because there is some dynamic placement for this loading gif. see here (RefreshLoader())
    • possibly do something similar to the label?
• Have the gif be transparent if possible, that way we can maybe theme for white in the future without having any issues
• remove references to old loading gif

[Segergren]

Reused the pictureBox1 and removed the old references.
Transparent GIFs doesn't work well with background color when I tried. And I would also use darker color for the second (white) color in the loading gif.

[lulzsun]

Looks good. Thanks!