JS: Accept trivial test changes

This adds Alert annotations for alerts that seem intentional by the test
but has not been annotated with 'NOT OK', or the comment was in the wrong
place.

In a few cases I included 'Source' expectations to make it easier to see
what happened. Other 'Source' expectations will be added in bulk a later
commit.

javascript/ql/test/query-tests/Expressions/SuspiciousInvocation/optional-chaining.js

@@ -1,9 +1,9 @@
 (function(){
     var a = null;
-    a();
+    a(); // $ Alert
     a?.();
 
     var b = undefined;
-    b();
+    b(); // $ Alert
     b?.();
 });