Enhancement: Open in specific web provider

We've added the specific web app providers instead of opening the file with the default web provider.

The user can open their files with any of the available specific web app providers from the server.
Previously, file was opened with the default one.

https://github.com/owncloud/android/issues/3994
https://github.com/owncloud/android/pull/3990
https://owncloud.dev/services/app-registry/apps/#app-registry
