Moved JUnit test to server-side source folder where it belongs

tests/testbench/com/vaadin/tests/components/datefield/ResolutionTest.java → tests/server-side/com/vaadin/tests/server/component/datefield/ResolutionTest.java

@@ -1,4 +1,4 @@
-package com.vaadin.tests.components.datefield;
+package com.vaadin.tests.server.component.datefield;
 
 import java.util.ArrayList;