Add convert to Legacy Seed

.github/workflows/push.yml

@@ -0,0 +1,22 @@
+name: Dart CI
+
+on:
+  push:
+    branches: [ trunk ]
+  pull_request:
+    branches: [ trunk ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dart-lang/setup-dart@v1
+        with:
+          sdk: stable
+
+      - name: Install dependencies
+        run: dart pub get
+
+      - name: Run tests
+        run: dart pub run test

example/polyseed_example.dart

@@ -1,7 +1,6 @@
 import 'dart:convert';
 
 import 'package:polyseed/polyseed.dart';
-import 'package:polyseed/src/utils/key_utils.dart';
 
 void main() {
   var lang = PolyseedLang.getByName("English");
@@ -27,13 +26,22 @@ void main() {
       Polyseed.decode(seedFeatherStr, lang, PolyseedCoin.POLYSEED_MONERO);
 
   var key = seedFeather.generateKey(PolyseedCoin.POLYSEED_MONERO, 32);
+
   print(seedFeather.birthday); // 1693622412
-  print(keyToHexString(
-      key)); // cbbd142d38347773d44aa830f5f01442aa6d0d3bb48571884479531248e6fa1c
-  print(base64.encode(
-      seedFeather.save())); //UE9MWVNFRUQWAP7QTFMwyWZ55hIVJOa7aluTxzP/Y3c=
+
+  print(key.toHexString());
+  // cbbd142d38347773d44aa830f5f01442aa6d0d3bb48571884479531248e6fa1c
+
+  print(base64.encode(seedFeather.save()));
+  //UE9MWVNFRUQWAP7QTFMwyWZ55hIVJOa7aluTxzP/Y3c=
 
   var seedLoaded = Polyseed.load(
       base64.decode("UE9MWVNFRUQWAP7QTFMwyWZ55hIVJOa7aluTxzP/Y3c="));
   print("seedLoaded: ${seedLoaded.encode(lang, PolyseedCoin.POLYSEED_MONERO)}");
+  // seedLoaded: unaware yard donate shallow slot sing oil oxygen loyal bench near hill surround forum execute lamp
+
+  var legacySeed =
+      seedFeather.toLegacySeed(LegacySeedLang.getByName("English"));
+  print("25 Word Legacy Seed: $legacySeed");
+  // 25 Word Legacy Seed: avidly chlorine gave yeti ramped certain hybrid comb governing amply hinder pamphlet offend geometry narrate unopened robot epoxy annoyed glide ingested ascend were austere unopened
 }

lib/polyseed.dart

@@ -1,5 +1,8 @@
 library polyseed;
 
+export 'src/mnemonics/legacy/legacy_seed_lang.dart';
+export 'src/mnemonics/polyseed_lang.dart';
 export 'src/polyseed.dart';
 export 'src/polyseed_coin.dart';
-export 'src/mnemonics/polyseed_lang.dart';
+export 'src/utils/legacy_polyseed_extension.dart';
+export 'src/utils/string_uint8list_extension.dart';