* Move onClick logic to the Connector
Move onClick event handling from 'VNativeButton' to NativeButtonConnector. Now works as for regular button.
Also, adding propagation of the `enabled` value to the state on disableOnClick being true
Fixes https://github.com/vaadin/framework/issues/11188
Add additional class names and style to components and error indicators to distinguish different error levels.
Vaadin 8 implementation of #9816. Cherry picked changes and added compatibility package component changes and tests.
Resolves #3139