KCL: Add diameter arg to circle (#7116)

Paul's been requesting this for a long time. Now that we're fully using keyword args, this is easy to do.

We should probably add a similar `diameter` arg to `arc`, `tangentialArc`, `polygon` etc. And _maybe_ to `fillet`, but that might not be as helpful.

rust/kcl-lib/src/docs/mod.rs

@@ -1018,7 +1018,7 @@ mod tests {
         let snippet = circle_fn.to_autocomplete_snippet();
         assert_eq!(
             snippet,
-            r#"circle(center = [${0:3.14}, ${1:3.14}], radius = ${2:3.14})"#
+            r#"circle(center = [${0:3.14}, ${1:3.14}], diameter = ${2:3.14})"#
         );
     }