qmljs: correctly handle required and readonly properties

* correct indentation after required property QTCREATORBUG-24144
* handle required <name> statement
* allow default readoly required reordering
* more permissive than the actual parser (which then will show errors
for invalid sequences)
* backport form QmlDom

Fixes: QTCREATORBUG-24144
Change-Id: I19166ca65d108d533a1ed3748c09e35bcfdbc56d
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/libs/qmljs/qmljsreformatter.cpp

@@ -669,6 +669,14 @@ protected:
         return false;
     }
 
+    bool visit(UiRequired *ast) override
+    {
+        out(ast->requiredToken);
+        out(" ");
+        out(ast->name.toString());
+        return true;
+    }
+
     bool visit(UiObjectBinding *ast) override
     {
         if (ast->hasOnToken) {