Add FrontendManager to manage non-default front-end impl (#3897)

* Add frontend manager

* Add tests

* nit

* Add unit test to github CI

* Fix path

* nit

* ignore

* Add logging

* Install test deps

* Remove 'stable' keyword support

* Update test

* Add web-root arg

* Rename web-root to front-end-root

* Add test on non-exist version number

* Use repo owner/name to replace hard coded provider list

* Inline cmd args

* nit

* Fix unit test

server.py

@@ -25,9 +25,10 @@ import mimetypes
 from comfy.cli_args import args
 import comfy.utils
 import comfy.model_management
-
+from app.frontend_management import FrontendManager
 from app.user_manager import UserManager
 
+
 class BinaryEventTypes:
     PREVIEW_IMAGE = 1
     UNENCODED_PREVIEW_IMAGE = 2
@@ -83,8 +84,12 @@ class PromptServer():
         max_upload_size = round(args.max_upload_size * 1024 * 1024)
         self.app = web.Application(client_max_size=max_upload_size, middlewares=middlewares)
         self.sockets = dict()
-        self.web_root = os.path.join(os.path.dirname(
-            os.path.realpath(__file__)), "web")
+        self.web_root = (
+            FrontendManager.init_frontend(args.front_end_version)
+            if args.front_end_root is None
+            else args.front_end_root
+        )
+        logging.info(f"[Prompt Server] web root: {self.web_root}")
         routes = web.RouteTableDef()
         self.routes = routes
         self.last_node_id = None