feat: convert Settings to dropdown menu with sub-items

- Convert Settings menu item to dropdown (similar to Contributions)
- Add Global Settings and Roles as sub-items
- Update German translations: 'Global Settings' and 'Roles'

priv/gettext/default.pot

@@ -558,6 +558,7 @@ msgid "Search..."
 msgstr ""
 
 #: lib/mv_web/components/layouts/navbar.ex
+#: lib/mv_web/live/role_live/index.html.heex
 #, elixir-autogen, elixir-format
 msgid "Users"
 msgstr ""
@@ -965,6 +966,7 @@ msgstr ""
 msgid "Fixed after creation. Members can only switch between types with the same interval."
 msgstr ""
 
+#: lib/mv_web/components/layouts/navbar.ex
 #: lib/mv_web/live/membership_fee_settings_live.ex
 #, elixir-autogen, elixir-format
 msgid "Global Settings"
@@ -1976,3 +1978,8 @@ msgstr ""
 #, elixir-autogen, elixir-format
 msgid "Role deleted successfully."
 msgstr ""
+
+#: lib/mv_web/components/layouts/navbar.ex
+#, elixir-autogen, elixir-format
+msgid "Roles"
+msgstr ""