Linux support v2 (resolve filepath v2)

[LovelySanta]

New attempt after #13, This resolves #13.

This add postbuildcommands for Sandbox:

• In debug mode & release mode we copy assets to the bin location
• In dist mode we remove the old assets first, to make sure removed assets are also removed from distribution. Then we copy the assets as before.

[LovelySanta]

Compiles & runs for WhoseTheNerd on Linux (Arch).
Compiles & runs for me on Windows
Compiles for me on Linux (WSL, so can't test running)
if it runs for @DaveAxiom we can push this

[DaveAxiom]

The asset directory was copied to ../bin/Debug-linux-x86_64/Sandbox/Sandbox and it ran.

I'm going to see if I can create a cleaner solution later today with a relative path. I believe you found that obtaining the executable's location isn't straight forward.

[LovelySanta]

I'm going to see if I can create a cleaner solution later today with a relative path. I believe you found that obtaining the executable's location isn't straight forward.

Now it is using the relative path as cherno coded it in the video.. And yes, it is indeed not straight forward to find the executable's location.

EDIT: Since this is using a relative path; where this will work in distribute/release as well, can you approve of this @DaveAxiom? It is working on Debian (me) and Arch (WhoseTheNerd).