[TF:XLA] Implement QuantizeAndDequantizeV3.

Change XLA lowering of QuantizeAndDequantizeV2/V3 to match the TF kernel much more closely. The main exception is the min_quantized and max_quantized values are calculated as floats to avoid the need for 64-bit integer math, which is not present on all accelerators.

Reformats unary_ops_test.py in passing, but on the whole I don't mind the reformatting.

PiperOrigin-RevId: 202395114