Feature - Add ability to configure "batch size" or auto-detect better values

[th3raid0r]

Currently, when using this tool, my RTX 3080 Ti is pretty under-utilized, especially with VRAM. This headroom indicates I could likely process more images per batch.

Given that I already supply VRAM/RAM information this could be auto-detected. However, a slider of reasonable values based on the RAM selection and video image size could also work.