Change: Add default action to click on file name

When clicking on the file name in the files list, a default action is triggered which opens the first available file editor or viewer.
If no file editor or viewer is available, the default action falls back to download.

https://github.com/owncloud/product/issues/234
https://github.com/owncloud/web/pull/4076
https://github.com/owncloud/web/pull/4097
