Add checkstyle

[plozanol]

As a developer, I want to add checkstyle code quality stage to GitHub actions before code build.

Acceptance:

• warnings will be treated as errors
• use the latest google style template up to date, if needed we will adapt rules to our team style:
  https://github.com/checkstyle/checkstyle/blob/master/src/main/resources/google_checks.xml
• add maven pom.xml dependencies and plugin config
• add GitHub action stage