When `showFederatedSharesToTrustedServersAsInternal` is enabled, the
trusted server filter was incorrectly applied to both internal and
external sharing sections. This prevented users from sharing with
federated users on non-trusted servers via the external share UI.
The filter now only applies to the internal section, allowing
non-trusted federated shares to appear in the external section.
Fixes: https://github.com/nextcloud/server/issues/56622
Signed-off-by: nfebe <fenn25.fn@gmail.com>