Properly respect associativity when reformatting (#7486)

Signed-off-by: Nick Cameron <nrc@ncameron.org>

rust/kcl-lib/src/parsing/ast/types/mod.rs

@@ -3005,6 +3005,8 @@ impl BinaryOperator {
         }
     }
 
+    /// The operator associativity of the operator (as in the parsing sense, not the mathematical sense of associativity).
+    ///
     /// Follow JS definitions of each operator.
     /// Taken from <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_precedence#table>
     pub fn associativity(&self) -> Associativity {
@@ -3015,6 +3017,12 @@ impl BinaryOperator {
             Self::And | Self::Or => Associativity::Left,
         }
     }
+
+    /// Whether an operator is mathematically associative. If it is, then the operator associativity (given by the
+    /// `associativity` method) is mostly irrelevant.
+    pub fn associative(&self) -> bool {
+        matches!(self, Self::Add | Self::Mul | Self::And | Self::Or)
+    }
 }
 #[derive(Debug, Clone, Deserialize, Serialize, PartialEq, ts_rs::TS, JsonSchema)]
 #[ts(export)]