Add support for server plugin (#1384)

## Description
PR to add support for a Wholphin server plugin:
https://github.com/damontecres/jellyfin-plugin-wholphin

Note: The plugin is not required to use Wholphin. It adds features the
server admin can use to set default settings like the home page or
eventually Seerr connection info.

### Changes
Wholphin will use the home page settings in order of:
1. Saved on the device locally
2. Saved on the server in the user's profile settings (display
preferences)
3. Provided by `jellyfin-plugin-wholphin`
4. Default fallback: combined continue watching & recently added in
libraries

Under customize home page, you can now see the "source" of the home
settings. This also allows to pick a different source

Finally, instead of the home customization being saved in the background
only locally, if there are any changes, a dialog is shown with options
to save locally, server-side user profile, or discard.

So overall, it's more clear where the home page settings are from and
where the user wants to save them.

### Install

[See instructions
here](https://github.com/damontecres/Wholphin/releases/tag/develop-server-plugin)

### Related issues
Related to #598

### Testing
WIP

## Screenshots
N/A

## AI or LLM usage
None

---------

Co-authored-by: Mario Reisinger <marioreisinger95@gmail.com>

app/src/main/res/values/strings.xml

@@ -967,4 +967,11 @@
     <string name="chosen_by">Chosen by %1$s</string>
     <string name="user">User</string>
     <string name="series">Series</string>
+    <string name="load_from_server_plugin">Load default from server</string>
+    <string name="save_to_local">Save only to this device</string>
+    <string name="home_settings_source_unset">Default</string>
+    <string name="home_settings_source_local">Device specific</string>
+    <string name="home_settings_source_server_profile">Server user profile</string>
+    <string name="home_settings_source_plugin">Server default</string>
+    <string name="home_settings_source_web">User web client</string>
 </resources>