clipboard actions are hidden when screen height is too small

The data list in the nuxeo-clipboard drawer shouldn't have min-height set to 500px as it pushes the actions down outside of the screen if the window is too small. 

In the task drawer, the data list min-height is set to auto:

https://github.com/nuxeo/nuxeo-web-ui/blob/c0af8156b41675bb9f1d5c2c0278c842fdcc74ae/elements/nuxeo-tasks/nuxeo-tasks-list.js#L89