Refactor flattenedRoute to improve component merging logic

- Changed the way components are handled within flattenedRoute to ensure child components are merged correctly.
- Introduced a temporary childComponents object to avoid direct mutation of the components object.
- Updated the logic to ensure that mergedComponents reflect the correct structure after processing child routes.

Author: SupertigerDev

package.json

@@ -1,6 +1,6 @@
 {
   "name": "solid-navigator",
-  "version": "0.3.14",
+  "version": "0.4.0",
   "description": "Solid Navigator is a library that is inspired by vue router and solid router.",
   "license": "MIT",
   "author": "SupertigerDev",