[ENH] New icons and splash screen

[markotoplak]

From material from biolab/orange-graphics@6e4cdf5

Apart from this some things will have to also be replaced in the installer repository. There are some icons there and the DMG screens.

I tried to cover everything in this repo, but very likely I missed something...

Before merging this test installers should be built.

See installers in ales-erjavec/orange3-installers#23

[codecov]

Codecov Report

Merging #5814 (d123b6f) into master (dfd2734) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #5814      +/-   ##
==========================================
- Coverage   86.14%   86.13%   -0.01%     
==========================================
  Files         316      316              
  Lines       66388    66419      +31     
==========================================
+ Hits        57187    57213      +26     
- Misses       9201     9206       +5     

[ajdapretnar]

I am so happy this is finally moving in the right direction.

I have some comments, though.

• The resolution of the images, at least on my 4k screen, seems very grainy.
• We should probably replace the colors of core categories, too? I think this was the idea at least.
• Welcome screen is still as it was. Are we keeping it this way or are there any changes planned?

Otherwise, the images are in the right place, so all good. But definitely have to test it with an installer.

[markotoplak]

* The resolution of the images, at least on my 4k screen, seems very grainy.

Which images? There are:

• It was just the icons, which are the same size and before (the largest being 256x256).
• And the splash screens, which are currently non-retina renders.

* Welcome screen is still as it was. Are we keeping it this way or are there any changes planned?

I'd leave it out of these. I do not think we agreed on anything there, for now.

[ajdapretnar]

Splash screens. Probably because they are non-retina.

[markotoplak]

@ajdapretnar, I do not have retinized splash screens ready, so I think that would be best handled in a different PR. Also the colors.

This PR would be best tested with builds from its companion installer PR: ales-erjavec/orange3-installers#23

I only tested the Mac installers.

[markotoplak]

Links for testing (both unsigned):

• Windows: https://ci.appveyor.com/api/buildjobs/3y51eg5j4jeje595/artifacts/installers%2FOrange3-3.32.0.dev0%2B13af216-Miniconda-x86_64.exe
• MacOS: https://dev.azure.com/ales-erjavec/64837369-9704-4f7c-a434-1fe8e78f627a/_apis/build/builds/130/artifacts?artifactName=macOS%20dmg%20installer&api-version=7.0&%24format=zip

[ajdapretnar]

I can confirm the .dmg installer works nicely for me.
We should keep in mind we are still "testing" #5712. So before the official release we should agree that we like the changes.

[thocevar]

Works fine on Windows as well.

[JakaKokosar]

Works fine on macOS Monterey (v12.1)

A minor thing about DMG folder style:

when I open the installer,

expected (make window size match the background image)