[Experimental Feature] FP8 weight dtype for base model when running train_network (or sdxl_train_network) (#1057)
* Add fp8 support
* remove some debug prints
* Better implementation for te
* Fix some misunderstanding
* as same as unet, add explicit convert
* better impl for convert TE to fp8
* fp8 for not only unet
* Better cache TE and TE lr
* match arg name
* Fix with list
* Add timeout settings
* Fix arg style
* Add custom seperator
* Fix typo
* Fix typo again
* Fix dtype error
* Fix gradient problem
* Fix req grad
* fix merge
* Fix merge
* Resolve merge
* arrangement and document
* Resolve merge error
* Add assert for mixed precision