fix: add dependency declaration and fix u!u8 token parsing

Author: kadinrabo

extensions/functions_arithmetic.yaml

@@ -1,6 +1,8 @@
 %YAML 1.2
 ---
 urn: extension:io.substrait:functions_arithmetic
+dependencies:
+  unsigned: extension:io.substrait:extension_types_numeric
 scalar_functions:
   -
     name: "add"

grammar/SubstraitType.g4

@@ -42,7 +42,15 @@ parameterizedType
   | List isnull=QMark? Lt expr Gt                                                           #list
   | Map isnull=QMark? Lt key=expr Comma value=expr Gt                                       #map
   | Func isnull=QMark? Lt params=funcParams Arrow returnType=expr Gt                        #func
-  | UserDefined Identifier isnull=QMark? (Lt expr (Comma expr)* Gt)?                        #userDefined
+  | UserDefined unsignedTypeName isnull=QMark? (Lt expr (Comma expr)* Gt)?                  #userDefined
+  ;
+
+unsignedTypeName
+  : Identifier
+  | U8
+  | U16
+  | U32
+  | U64
   ;
 
 funcParams