Add version history view for timer functions

- Implement `/history/<function_id>` route in timer routes to fetch and display function versions
- Create new Mithril `DiffView` component for comparing script versions
- Add new history template for timer functions with version comparison
- Include version diff functionality using AceDiff library
- Update header and edit templates to include history URL for timer functions

templates/dashboard/timer_functions/logs.html

@@ -9,7 +9,8 @@ show_logs=True,
 show_history=True,
 edit_url=url_for('timer.edit', function_id=function_id),
 cancel_url=url_for('timer.overview'),
-logs_url=url_for('timer.logs', function_id=function_id)) }}
+logs_url=url_for('timer.logs', function_id=function_id),
+history_url=url_for('timer.history', function_id=function_id)) }}
 
 <div class="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
     <div class="bg-white rounded-lg shadow-sm border border-gray-200 overflow-hidden">