feat: add ST_NumPoints alias for ST_NPoints

Closes part of #200.

Author: ajaypadwal73

rust/sedona-functions/src/st_points.rs

@@ -115,6 +115,7 @@ pub fn st_npoints_udf() -> SedonaScalarUDF {
         ItemCrsKernel::wrap_impl(vec![Arc::new(STNPoints)]),
         Volatility::Immutable,
     )
+    .with_aliases(vec!["st_numpoints".to_string()])
 }
 
 #[derive(Debug)]
@@ -296,6 +297,12 @@ mod tests {
         assert!(st_npoints_udf.documentation().is_none());
     }
 
+    #[test]
+    fn npoints_aliases() {
+        let udf: ScalarUDF = st_npoints_udf().into();
+        assert!(udf.aliases().contains(&"st_numpoints".to_string()));
+    }
+
     #[rstest]
     fn udf(#[values(WKB_GEOMETRY, WKB_GEOGRAPHY)] sedona_type: SedonaType) {
         use arrow_array::UInt64Array;