Enhance skill evaluation UI with category icons and URL state management

- Added category icons to the skill evaluation components for better visual representation.
- Implemented URL parameter handling in SkillEvaluation to maintain selected category state across navigation.
- Improved the HomePage layout with expandable skill categories and enhanced user interaction.
- Updated skill data files to include icon properties for each category.

data/skills/backend.json

@@ -1,5 +1,6 @@
 {
   "category": "Backend",
+  "icon": "server",
   "skills": [
     {
       "id": "nodejs",