Deprecate FileDataStorageManager constructors depending on legacy Account

This commit deprecates constructors using legacy platform Account type
and wraps them using new API accepting User model.

All calls to FileDataStorageManager constructors that were trivially
portable without are updated as well. Places where passing new type
requires more risku work were left out for now.

FileDataStorageManager still uses Account internally - modifying this
requires getting rid of all legacy constructors first.

Signed-off-by: Chris Narkiewicz <hello@ezaquarii.com>

src/debug/java/com/nextcloud/client/TestActivity.kt

@@ -38,6 +38,7 @@ import com.owncloud.android.ui.activity.FileActivity
 import com.owncloud.android.ui.activity.OnEnforceableRefreshListener
 import com.owncloud.android.ui.fragment.FileFragment
 import com.owncloud.android.ui.helpers.FileOperationsHelper
+import java.lang.RuntimeException
 
 class TestActivity :
     FileActivity(),