feat(web): make google cast opt in (#18514)

* add setting switch

this isnt bound to anything yet

* make google casting opt-in

* doc updates

* lint docs

* remove unneeded translation items

* update mobile openai defs

* fix failing test

we need to mock user prefs since CastButton uses it

mobile/openapi/lib/model/cast_update.dart

@@ -0,0 +1,108 @@
+//
+// AUTO-GENERATED FILE, DO NOT MODIFY!
+//
+// @dart=2.18
+
+// ignore_for_file: unused_element, unused_import
+// ignore_for_file: always_put_required_named_parameters_first
+// ignore_for_file: constant_identifier_names
+// ignore_for_file: lines_longer_than_80_chars
+
+part of openapi.api;
+
+class CastUpdate {
+  /// Returns a new [CastUpdate] instance.
+  CastUpdate({
+    this.gCastEnabled,
+  });
+
+  ///
+  /// Please note: This property should have been non-nullable! Since the specification file
+  /// does not include a default value (using the "default:" property), however, the generated
+  /// source code must fall back to having a nullable type.
+  /// Consider adding a "default:" property in the specification file to hide this note.
+  ///
+  bool? gCastEnabled;
+
+  @override
+  bool operator ==(Object other) => identical(this, other) || other is CastUpdate &&
+    other.gCastEnabled == gCastEnabled;
+
+  @override
+  int get hashCode =>
+    // ignore: unnecessary_parenthesis
+    (gCastEnabled == null ? 0 : gCastEnabled!.hashCode);
+
+  @override
+  String toString() => 'CastUpdate[gCastEnabled=$gCastEnabled]';
+
+  Map<String, dynamic> toJson() {
+    final json = <String, dynamic>{};
+    if (this.gCastEnabled != null) {
+      json[r'gCastEnabled'] = this.gCastEnabled;
+    } else {
+    //  json[r'gCastEnabled'] = null;
+    }
+    return json;
+  }
+
+  /// Returns a new [CastUpdate] instance and imports its values from
+  /// [value] if it's a [Map], null otherwise.
+  // ignore: prefer_constructors_over_static_methods
+  static CastUpdate? fromJson(dynamic value) {
+    upgradeDto(value, "CastUpdate");
+    if (value is Map) {
+      final json = value.cast<String, dynamic>();
+
+      return CastUpdate(
+        gCastEnabled: mapValueOfType<bool>(json, r'gCastEnabled'),
+      );
+    }
+    return null;
+  }
+
+  static List<CastUpdate> listFromJson(dynamic json, {bool growable = false,}) {
+    final result = <CastUpdate>[];
+    if (json is List && json.isNotEmpty) {
+      for (final row in json) {
+        final value = CastUpdate.fromJson(row);
+        if (value != null) {
+          result.add(value);
+        }
+      }
+    }
+    return result.toList(growable: growable);
+  }
+
+  static Map<String, CastUpdate> mapFromJson(dynamic json) {
+    final map = <String, CastUpdate>{};
+    if (json is Map && json.isNotEmpty) {
+      json = json.cast<String, dynamic>(); // ignore: parameter_assignments
+      for (final entry in json.entries) {
+        final value = CastUpdate.fromJson(entry.value);
+        if (value != null) {
+          map[entry.key] = value;
+        }
+      }
+    }
+    return map;
+  }
+
+  // maps a json object with a list of CastUpdate-objects as value to a dart map
+  static Map<String, List<CastUpdate>> mapListFromJson(dynamic json, {bool growable = false,}) {
+    final map = <String, List<CastUpdate>>{};
+    if (json is Map && json.isNotEmpty) {
+      // ignore: parameter_assignments
+      json = json.cast<String, dynamic>();
+      for (final entry in json.entries) {
+        map[entry.key] = CastUpdate.listFromJson(entry.value, growable: growable,);
+      }
+    }
+    return map;
+  }
+
+  /// The list of required keys that must be present in a JSON.
+  static const requiredKeys = <String>{
+  };
+}
+