[Utakaze] Result対応

[blhsrwznrghfzpr]

#423 の「小さな勇者のRPG ウタカゼ」の対応です。

ウタカゼの行為判定コマンドは成功レベル（成功度や達成値のようなもの）を求めるコマンドですが、
通常の判定では単に成功/失敗だけを確認することが多いので、
難易度指定なしの場合でも成功レベルがあればsuccessとして扱っています

[codecov]

Codecov Report

Merging #468 (5e27237) into master (7c0b4e7) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #468      +/-   ##
==========================================
- Coverage   95.26%   95.26%   -0.01%     
==========================================
  Files         290      290              
  Lines       18783    18780       -3     
==========================================
- Hits        17893    17890       -3     
  Misses        890      890              

Impacted Files	Coverage Δ
lib/bcdice/game_system/Utakaze.rb	100.00% <100.00%> (ø)

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[ysakasin]

ありがとうございます！