feat(components): Add markdown editing capability and enhance component styling

- Add editable mode to Markdown component with edit/save/cancel buttons
- Import EditOutlined, SaveOutlined, CloseOutlined icons from ant-design
- Add useState, useRef, useEffect hooks for managing edit state
- Add editable, onContentChange, and onSave props to RbMarkdownProps interface
- Create RbModal component with new index.css stylesheet for modal styling
- Add index.css stylesheet to KnowledgeBase components for consistent styling
- Update i18n translations in en.ts and zh.ts for new UI elements
- Refactor Markdown component handlers to accept and spread additional props
- Update InsertModal and RecallTestResult components for improved UX
- Fix prop spreading in component handlers to maintain compatibility with Ant Design components

web/src/components/RbModal/index.css

@@ -0,0 +1,3 @@
+.rb-modal .ant-modal-header {
+  margin-bottom: 24px;
+}