Change: Render error and warning messages in oc-text-input

The oc-text-input element now has properties for rendering a warning or error message below
the input field. The input field border receives the respective matching color as well. Also
it's possible to reserve a fixed vertical space below the input element, so that an appearing
message doesn't break the layout around the input element.

https://github.com/owncloud/owncloud-design-system/issues/689
https://github.com/owncloud/owncloud-design-system/pull/690

