feat: add arithmetic function "sqrt" and "factorial" with decimal type

extensions/functions_arithmetic_decimal.yaml

@@ -102,7 +102,7 @@ scalar_functions:
           scale_after_borrow = max(init_scale - delta, min_scale)
           scale = init_prec > 38 ? scale_after_borrow : init_scale
           DECIMAL<prec, scale>
-  - 
+  -
     name: "abs"
     description: Calculate the absolute value of the argument.
     impls:
@@ -111,6 +111,23 @@ scalar_functions:
             value: decimal<P,S>
         return: decimal<P,S>
 
+  - name: "sqrt"
+    description: Square root of the value. Sqrt of 0 is 0 and sqrt of negative values will raise an error.
+    impls:
+      - args:
+          - name: x
+            value: "DECIMAL<P,S>"
+        return: fp64
+  - name: "factorial"
+    description: >
+      Return the factorial of a given decimal input. Scale should be 0 for factorial decimal input.
+      The factorial of 0! is 1 by convention. Negative inputs will raise an error.
+      Input which cause overflow of result will raise an error.
+    impls:
+      - args:
+          - name: "n"
+            value: "DECIMAL<P,0>"
+        return: "DECIMAL<38,0>"
 aggregate_functions:
   - name: "sum"
     description: Sum a set of values.