usb: unify ControlHandler+DeviceStateHandler, route all control requests to all handlers.

- Allows classes to handle vendor requests.
- Allows classes to use a single handler for multiple interfaces.
- Allows classes to access the other events (previously only `reset` was available).

embassy-usb/Cargo.toml

@@ -27,6 +27,15 @@ max-interface-count-6 = []
 max-interface-count-7 = []
 max-interface-count-8 = []
 
+max-handler-count-1 = []
+max-handler-count-2 = []
+max-handler-count-3 = []
+max-handler-count-4 = [] # Default
+max-handler-count-5 = []
+max-handler-count-6 = []
+max-handler-count-7 = []
+max-handler-count-8 = []
+
 # END AUTOGENERATED CONFIG FEATURES
 
 [dependencies]