feat: add ht_preferences clients

- Added ht_preferences_client dep
- Added ht_preferences_firestore dep

Author: fulleni

pubspec.yaml

@@ -65,6 +65,12 @@ dependencies:
   ht_kv_storage_shared_preferences:
     git:
       url: https://github.com/headlines-toolkit/ht-kv-storage-shared-preferences.git
+  ht_preferences_client:
+    git:
+      url: https://github.com/headlines-toolkit/ht-preferences-client.git
+  ht_preferences_firestore:
+    git:
+      url: https://github.com/headlines-toolkit/ht-preferences-firestore.git
   ht_shared:
     git:
       url: https://github.com/headlines-toolkit/ht-shared.git