feat(create-category): add create category events

- Define base CreateCategoryEvent
- Add name and description events
- Include icon URL

Author: fulleni

lib/content_management/bloc/create_category/create_category_event.dart

@@ -0,0 +1,38 @@
+part of 'create_category_bloc.dart';
+
+/// Base class for all events related to the [CreateCategoryBloc].
+sealed class CreateCategoryEvent extends Equatable {
+  const CreateCategoryEvent();
+
+  @override
+  List<Object> get props => [];
+}
+
+/// Event for when the category's name is changed.
+final class CreateCategoryNameChanged extends CreateCategoryEvent {
+  const CreateCategoryNameChanged(this.name);
+  final String name;
+  @override
+  List<Object> get props => [name];
+}
+
+/// Event for when the category's description is changed.
+final class CreateCategoryDescriptionChanged extends CreateCategoryEvent {
+  const CreateCategoryDescriptionChanged(this.description);
+  final String description;
+  @override
+  List<Object> get props => [description];
+}
+
+/// Event for when the category's icon URL is changed.
+final class CreateCategoryIconUrlChanged extends CreateCategoryEvent {
+  const CreateCategoryIconUrlChanged(this.iconUrl);
+  final String iconUrl;
+  @override
+  List<Object> get props => [iconUrl];
+}
+
+/// Event to signal that the form should be submitted.
+final class CreateCategorySubmitted extends CreateCategoryEvent {
+  const CreateCategorySubmitted();
+}