[FIX] web: properly apply styles attribute to form fields

The form widgets did not apply the 'style' attribute to the result of
the rendering.  Because of that, many small adjustment were no longer
possible. This commit makes sure that it is indeed done.

addons/web/static/src/js/views/form_common.js

@@ -430,6 +430,7 @@ var FormWidget = Widget.extend(InvisibilityChangerMixin, {
         this.process_modifiers();
         this._super();
         this.$el.addClass(this.node.attrs["class"] || "");
+        this.$el.attr('style', this.node.attrs.style);
     },
     destroy: function() {
         $.fn.tooltip('destroy');