make it possible for scripts to add cross attention optimizations

add UI selection for cross attention optimization

modules/shared_items.py

@@ -21,3 +21,11 @@ def refresh_vae_list():
     import modules.sd_vae
 
     modules.sd_vae.refresh_vae_list()
+
+
+def cross_attention_optimizations():
+    import modules.sd_hijack
+
+    return ["Automatic"] + [x.title() for x in modules.sd_hijack.optimizers] + ["None"]
+
+