fix: use only one function and add skip_null option

extensions/functions_comparison.yaml

@@ -218,33 +218,19 @@ scalar_functions:
   -
     name: "least"
     description: >-
-      Returns the smallest value.
+      Returns the smallest value.  The function will return null if any argument evaluates
+      to null.
 
-      The `null_handling` option specifies how to handle null arguments.  If `ANY_NULL`
-      is specified, the function will return null if any argument evaluate to null.
-      `ALL_NULLS` means the function will return null only if all arguments evaluate to null.
+      Enabling the `skip_null` will return null only if all arguments evaluate to null.
 
       String comparison is done in lexicographical ordering, one character at a time, from
       left to right. Uppercase letters are less than lowercase letters.
     impls:
       - args:
           - value: T
         options:
-          null_handling:
-            values: [ ANY_NULL, ALL_NULLS ]
-        variadic:
-          min: 2
-        return: T|?
-  -
-    name: "least_skip_null"
-    description: >-
-      Returns the smallest value. Skip any null arguments.
-
-      String comparison is done in lexicographical ordering, one character at a time, from
-      left to right. Uppercase letters are less than lowercase letters.
-    impls:
-      - args:
-          - value: T
+          skip_null:
+            values: [ ENABLED ]
         variadic:
           min: 2
         return: T