Binding one or more one-way write URIs for a database and auto overwrite those URIs

**Is your feature request related to a problem? Please describe.**

When device is lost or damaged, the Keepass database may get lost forever. Setting up a backup task can mend this, but it requires another app to be opened, which is trifle and not as convinient as auto backup when saving in KeepassDX.

**Describe the solution you'd like**

Bind one or more backup URIs to a database in KeepassDX. Those URIs are provided by content provider such as OneDrive App or other File Manager.

After saving database, KeepassDX over write the database to the URIs bund before.

So KeepassDX don't need to introduce built-in file manager or remote utility or internet permission, while users can easily auto upload the newest database to remote storage.

**Describe alternatives you've considered**

I use Mixplorer to do the backup things for now, but Mixplorer is alway not in the background, so the timer task ususlly don't work, turned out I still have to manually backup the database to my cloud disk.

The request concerns KeePassDX database saves and one-way backup URIs supplied by Android content providers such as OneDrive or a file manager. Start by locating the database save flow and how content-provider URIs could be retained. Done means a database can bind one or more URIs and overwrite each backup after saving without requiring another app to run manually.

Written by the indexing model from the issue text.