WASM Emulator: Ability to upload .out files and to mount FAT32 file systems via upload

[sy2002]

In the meantime, thanks to the font gfx and sprites - and also the timer - we have so much interessting (and complex) example code to test, that an ability to upload something to the WASM emulator becomes mandatory for testing: Does the WASM emulator work with all the new "inventions" of V1.7?

Right now, the process to test something on WASM is extremely cumbersome, because you always need a file system image and you need to change the code.

Therefore, we need two things - and this issue is about these two things:

1. Ability to upload .out files (maybe directly fill them into the emulator's RAM)

2. Ability to mount FAT32 file systems via upload