Refactor account page to use icon in form title

- Remove redundant page heading from account page
- Add AccountCircle icon to AccountForm title
- Clean up unused account-page translations
- Simplify account page component by moving title to form

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

messages/hr.json

@@ -130,9 +130,6 @@
       "location-name-required": "Ime nekretnine je obavezno"
     }
   },
-  "account-page": {
-    "heading": "Postavke Računa"
-  },
   "account-form": {
     "title": "Podaci o profilu",
     "first-name-label": "Ime",