feat: add PhotoMaker Version 2 support (#358)

* first attempt at updating to photomaker v2

* continue adding photomaker v2 modules

* finishing the last few pieces for photomaker v2; id_embeds need to be done by a manual step and pass as an input file

* added a name converter for Photomaker V2; build ok

* more debugging underway

* failing at cuda mat_mul

* updated chunk_half to be more efficient; redo feedforward

* fixed a bug: carefully using ggml_view_4d to get chunks of a tensor; strides need to be recalculated or set properly; still failing at soft_max cuda op

* redo weight calculation and weight*v

* fixed a bug now Photomaker V2 kinds of working

* add python script for face detection (Photomaker V2 needs)

* updated readme for photomaker

* fixed a bug causing PMV1 crashing; both V1 and V2 work

* fixed clean_input_ids for PMV2

* fixed a double counting bug in tokenize_with_trigger_token

* updated photomaker readme

* removed some commented code

* improved reconstructing class word free prompt

* changed reading id_embed to raw binary using existing load tensor function; this is more efficient than using model load and also makes it easier to work with sd server

* minor clean up

---------

Co-authored-by: bssrdf <bssrdf@gmail.com>

docs/photo_maker.md

@@ -29,4 +29,26 @@ Example:
 
 ```bash
 bin/sd -m ../models/sdxlUnstableDiffusers_v11.safetensors  --vae ../models/sdxl_vae.safetensors --stacked-id-embd-dir ../models/photomaker-v1.safetensors --input-id-images-dir ../assets/photomaker_examples/scarletthead_woman -p "a girl img, retro futurism, retro game art style but extremely beautiful, intricate details, masterpiece, best quality, space-themed, cosmic, celestial, stars, galaxies, nebulas, planets, science fiction, highly detailed" -n "realistic, photo-realistic, worst quality, greyscale, bad anatomy, bad hands, error, text" --cfg-scale 5.0  --sampling-method euler -H 1024 -W 1024 --style-ratio 10 --vae-on-cpu -o output.png
-```
+```
+
+## PhotoMaker Version 2
+
+[PhotoMaker Version 2 (PMV2)](https://github.com/TencentARC/PhotoMaker/blob/main/README_pmv2.md) has some key improvements. Unfortunately it has a very heavy dependency which makes running it a bit involved in ```SD.cpp```. 
+
+Running PMV2 is now a two-step process:
+
+- Run a python script ```face_detect.py``` to obtain **id_embeds** for the given input images
+```
+python face_detect.py input_image_dir
+```
+An ```id_embeds.safetensors``` file will be generated in ```input_images_dir```
+
+**Note: this step is only needed to run once; the same ```id_embeds``` can be reused**
+
+- Run the same command as in version 1 but replacing ```photomaker-v1.safetensors``` with ```photomaker-v2.safetensors```.
+
+  You can download ```photomaker-v2.safetensors``` from [here](https://huggingface.co/bssrdf/PhotoMakerV2)
+
+- All the command line parameters from Version 1 remain the same for Version 2
+
+