[WIP] optimize infer_auto_device_map for multi-GPU allocation

[Nech-C]

What does this PR do?

This PR continues to solve issues raised in #3041 and discussed in #3066. When multiple GPUs are present, reserving memory for max_layer_size can cause unnecessary offloading to the CPU or disks. The PR implements the approach proposed by @SunMarc. It works by first assuming no offloading is necessary, and if there are offloaded modules in the device map, it's recomputed, assuming offloading will occur.

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