Split CompanyController and introduce standalone User Settings page

Backend:
- Extract user profile methods (show, update, uploadAvatar) from
  CompanyController into new UserProfileController
- CompanyController now only handles company concerns (updateCompany,
  uploadCompanyLogo)
- Remove Account Settings from setting_menu config

Frontend:
- New /admin/user-settings page with 3 tabs: General, Profile Photo,
  Security (password change)
- User dropdown now links to /admin/user-settings instead of
  /admin/settings/account-settings
- Settings sidebar defaults to Company Information as first item
- Remove old monolithic AccountSetting.vue

resources/scripts/admin/layouts/partials/TheSiteHeader.vue

@@ -147,7 +147,7 @@
             />
           </template>
 
-          <router-link to="/admin/settings/account-settings">
+          <router-link to="/admin/user-settings">
             <BaseDropdownItem>
               <BaseIcon
                 name="CogIcon"