Implement checkstyle plugin with naming conventions validation

[p1gushka]

Description

Implement checkstyle plugin with naming conventions validation

Tasks

• add pom.xml plugin with params: consoleOutput=true, failOnViolation=true
• add checkstyle.xml with rules
  • TypeName
  • MethodName
  • LocalVariableName
  • MemberName
  • ParameterName
  • ConstantName, Exceptions: log, logger
  • PackageName
  • AvoidStarImport
  • UnusedImports
  • NeedBraces
  • OneStatementPerLine
  • SuppressWarnings annotation
• add checkstyle-suppressions.xml and link it in checkstyle.xml
• update ci.yml
• update CONTRIBUTING.md
  • Suppressing Guide section
  • workflow