"Modern A3D" file format and support

[Pyogenics]

After flash EOL in 2020 Alternativa rewrote their engine and main product, Tanki Online, in kotlin to deploy for mobile and HTML5. Recently I discovered that Alternativa has further extended the A3D model format past original A3D1 and A3D2 formats and is actively using it in Tanki Online. It only makes sense that this tool should also support the modern A3D formats, I will document my research and findings todo with this format here and in future may open a PR to follow up and add support for this newer format to my other PR.