Splitted resource and resource usage checkers.

Review: https://reviews.apache.org/r/28618
Added basic DiskInfo check in master.

Review: https://reviews.apache.org/r/28626
Added tests for basic DiskInfo checker.

Review: https://reviews.apache.org/r/28627
Added duplicated persistence id check in ResourceChecker.

Review: https://reviews.apache.org/r/28664