Associate .chn with chaiNNer on MacOS

[stonerl]

• added association of .chn filetype with chainner on macOS
• added file type icon
• added open-file event for macOS

This addresses #1062 but does not solve it completely, since file association only works on macOS ATM.

[RunDevelopment]

Thank you @stonerl!

Let's focus on .chn files for now. Opening models presents the problem that the PyTorch, ONNX, and NCNN packages may not be installed, so what are we supposed to do then? Also, there are no .ncnn files. NCNN stores models as 2 files: .param and .bin.

[stonerl]

Okay, changed it. It now only associates chaiNNer with .chn files.

[RunDevelopment]

Do we still need to other icons?

[stonerl]

Do we still need to other icons?

I would let them stay. The are not copied into the app, so no harm done. And if we decide to make use of them then we already have them.

[RunDevelopment]

Doesn't feel good to have unused files in the repository...

No, please remove them. Let's add them when we actually add support for opening model files.

[stonerl]

Okay, removed them.

[joeyballentine]

but double-clicking on them does not do any meaningful for now

Are you sure? On windows if I manually associate the file type, I'm able to open chain files directly by double clicking them. If that doesn't work on Mac, then I guess that means Mac uses different args when launching chaiNNer?

[stonerl]

@joeyballentine Yes, I tested it. Drag'n'drop does work, though. On macOS we need to use open-file, it seems.

Can you point me to the code where the drag'n'drop and file opening, e.g., on Windows is handled? I am uncertain whether I'm able to implement this for macOS, but I would give it a try.

[joeyballentine]

Arg parsing:

chaiNNer/src/main/arguments.ts

Line 30 in 11a75fc

.positional('file', {

Using the arg:

chaiNNer/src/main/gui/main-window.ts

Line 129 in 11a75fc

if (args.file) {

I believe on windows when you open a file with a program it adds the file as a positional arg. I guess this is not the case for MacOS then

[stonerl]

Opening .chn files by double-clicking them now also works on macOS.