Create a high-level `Button` React component that

• renders either a <button> (default) or an <a> node
• renders a label as provided as a property
• executes a handler on click as provided as a property
• renders an additonal semantic class(such as 'danger', 'success') as provided as a property

Also the necessary CSS needs to be written, for the time being in an apperance similar to buttons in current products (Cockpit, Optimize 1)