CodeLens or Inline values for embedded CRON expressions

[BoykoAlex]

CodeLens or Inline Values explaining what CRON expressions mean.

This should go in Java, and Properties/YAML for Spring Boot properties

Use org.springframework.scheduling.support.CronExpression from Spring Framework it has parse method that should produce expression object with all the data we'd want to show in a CodeLens

(See support for CRON in IntelliJ: https://www.jetbrains.com/help/idea/scheduled-tasks.html)