Revert "Refactoring changes for testing resource compatibility." as it breaks rum publishRestModel with this message "No such property: summary for class: com.linkedin.restli.tools.idlcheck.RestLiResourceModelCompatibilityChecker"

This reverts commit eec968ddab745286a8c9e05e35f0ddeab011a947.
bump to version 1.8.27
Add RB record to 1.8.27 CHANGELOG