Add support for private and hashtag channels in localization and channel management

- Updated Polish, Portuguese, Slovak, Slovenian, Swedish, and Chinese localization files to include new strings for creating and joining private channels, as well as joining hashtag channels.
- Enhanced the channel management UI to allow users to create and join private channels, join public channels, and join channels via hashtags.
- Implemented PSK derivation from hashtags using SHA256 in the Channel model.
- Improved the translation script to handle missing keys and translate all locales efficiently.

lib/l10n/app_de.arb

@@ -1335,5 +1335,17 @@
   "listFilter_repeaters": "Wiederholer",
   "listFilter_roomServers": "Raumserver",
   "listFilter_unreadOnly": "Nur nicht gelesen",
-  "listFilter_newGroup": "Neue Gruppe"
+  "listFilter_newGroup": "Neue Gruppe",
+  "channels_joinPrivateChannel": "Treten Sie einem privaten Kanal bei",
+  "channels_joinPrivateChannelDesc": "Manuelle Eingabe eines geheimen Schlüssels.",
+  "channels_createPrivateChannel": "Erstelle einen privaten Kanal",
+  "channels_createPrivateChannelDesc": "Verschlüsselt mit einem geheimen Schlüssel.",
+  "channels_joinPublicChannel": "Tritt dem öffentlichen Kanal bei",
+  "channels_joinPublicChannelDesc": "Jeder kann diesem Kanal beitreten.",
+  "channels_joinHashtagChannel": "Treten Sie einem Hashtag-Kanal bei",
+  "channels_joinHashtagChannelDesc": "Jeder kann sich bei Hashtag-Kanälen beteiligen.",
+  "channels_scanQrCode": "Scannen Sie einen QR-Code",
+  "channels_scanQrCodeComingSoon": "Bald verfügbar",
+  "channels_enterHashtag": "Gib Hashtag ein",
+  "channels_hashtagHint": "z.B. #team"
 }