Fix Checkpoint Merging #1359,#1095

[cluder]

see also #1359

• checkpoint_list[] contains the CheckpointInfo.title which is "checkpointname.safetensor [hash]" when a checkpoint is selected to be loaded during merge, we try to match it with just "checkpointname.safetensor". -> use checkpoint_aliases[] which already contains the checkpoint key in all possible variants.
• replaced removed sd_models.read_state_dict() with sd_models.load_torch_file()
• replaced removed sd_vae.load_vae_dict() with sd_vae.load_torch_file()
• uncommented create_config() for now, since it calls a removed method: sd_models_config.find_checkpoint_config_near_filename()

not sure what to do with create_config() it it even needed?