AppCenter doesn't show flatpak installed from bundles

## What Happened

if you install a .flatpak bundle, it won't appear on appcenter with the ones from repositories,
so the only way to remove then is via CLI.

## Expected Behavior

that flatpak installed from bundles appear on appcenter and make possible to remove them from here.

## Steps to Reproduce

1. install a .flatpak bundle using the flatpak CLI
2. look for the application on appcenter
3. the bundle installation doesn't appear

### Logs

## Platform Information

elementaryOS 6.0 Early Access