fix: enhance notifications and validation features

- Added URL validation for notification providers to ensure only valid http/https URLs are accepted.
- Implemented tests for URL validation scenarios in the Notifications component.
- Updated translations for error messages related to invalid URLs in multiple languages.
- Introduced new hooks for managing security headers and access lists in tests.
- Enhanced the ProviderForm component to reset state correctly when switching between add and edit modes.
- Improved user feedback with update indicators after saving changes to notification providers.
- Added mock implementations for new hooks in various test files to ensure consistent testing behavior.

frontend/src/components/__tests__/ProxyHostForm-dns.test.tsx

@@ -51,7 +51,15 @@ vi.mock('../../hooks/useSecurity', () => ({
 
 vi.mock('../../hooks/useSecurityHeaders', () => ({
   useSecurityHeaderProfiles: vi.fn(() => ({
-    profiles: [],
+    data: [],
+    isLoading: false,
+    error: null,
+  })),
+}))
+
+vi.mock('../../hooks/useAccessLists', () => ({
+  useAccessLists: vi.fn(() => ({
+    data: [],
     isLoading: false,
     error: null,
   })),