JS: Type track mssql model

javascript/ql/test/library-tests/frameworks/SQL/SqlString.expected

@@ -2,6 +2,7 @@
 | mssql1.js:7:75:7:79 | value |
 | mssql2.js:5:15:5:34 | 'select 1 as number' |
 | mssql2.js:13:15:13:66 | 'create ...  table' |
+| mssql2.js:22:24:22:43 | 'select 1 as number' |
 | mysql1.js:13:18:13:43 | 'SELECT ... lution' |
 | mysql1.js:18:18:22:1 | {\\n    s ... vid']\\n} |
 | mysql2.js:12:12:12:37 | 'SELECT ... lution' |

javascript/ql/test/library-tests/frameworks/SQL/mssql2.js

@@ -13,3 +13,13 @@ request.query('select 1 as number', (err, result) => {
 request.batch('create procedure #temporary as select * from table', (err, result) => {
     // ... error checks
 })
+
+class C {
+    constructor(req) {
+        this.req = req;
+    }
+    send() {
+        this.req.query('select 1 as number', (err, result) => {})
+    }
+}
+new C(new sql.Request());