Lift Assignment: process lambda assignments in when correctly

So #KT-23346 Fixed

idea/testData/inspectionsLocal/liftOut/tryToAssignment/lambda.kt

@@ -0,0 +1,9 @@
+fun test(b: Boolean) {
+    var fn: () -> String
+
+    <caret>try {
+        fn = { "foo" }
+    } catch (e: Exception) {
+        fn = { "bar" }
+    }
+}