fix: fix sonarcloud maintainability

[vvatanabe]

• fix the code smell warnings in ClasspathResource
• fix the code smell warnings in StandardKeyboards
• fix the code smell warnings in StandardDictionaries
• fix the code smell warnings in Pattern
• fix the code smell warnings in EstimateGuess
• fix the code smell warnings in DictionaryGuess
• fix the code smell warnings in WipeableString
• fix the code smell warnings in TimeEstimates
• fix the code smell warnings in StandardContext
• fix the code smell warnings in FeedbackFactory
• fix the code smell warnings in Feedback

[coveralls]

coverage: 92.504% (-0.4%) from 92.926% when pulling d470552 on fix-sonarcloud-maintainability into 3d29dbd on main.