Select residence country by searchable name (#64)

frontend/app/lib/kyc/profile.dart

@@ -2,6 +2,8 @@ import 'package:flutter/material.dart';
 
 import 'package:sxchnge_kyc/sxchnge_kyc.dart';
 
+import 'country.dart';
+
 import '../generated/i18n/app_localizations.dart';
 
 class ProfileForm extends StatelessWidget {
@@ -48,17 +50,11 @@ class ProfileForm extends StatelessWidget {
           onChanged: (value) => update(birth: value.trim()),
         ),
         const SizedBox(height: 16),
-        TextFormField(
+        CountryField(
           key: const ValueKey('kyc-country'),
-          initialValue: p.profile.residenceCountry,
+          value: p.profile.residenceCountry,
           enabled: !p.busy,
-          maxLength: 2,
-          textCapitalization: TextCapitalization.characters,
-          decoration: InputDecoration(
-            labelText: l.kycCountry,
-            helperText: l.kycCountryHelp,
-          ),
-          onChanged: (value) => update(country: value.trim().toUpperCase()),
+          onChanged: (value) => update(country: value),
         ),
         if (!p.profile.isComplete) Text(l.kycProfileRequired),
       ],