HDDS-9242. Merge unit and integration checks into a combined one
What changes were proposed in this pull request?
Unit and integration tests are currently run in separate checks. Integration tests are split into parallel runs to reduce CI wall clock time. Unit tests, however, are run in one check, which is now one of the slowest ones.
This PR changes integration check to also execute unit tests, to benefit from running them in parallel splits.
It also rebalances splits by creating some new ones and merging contract into filesystem.
Some tests related to snapshots are moved from org.apache.hadoop.ozone.om to org.apache.hadoop.ozone.om.snapshot to reduce the time required for integration (om) check.
https://issues.apache.org/jira/browse/HDDS-9242
How was this patch tested?
Checked CI output to verify total number of tests across all splits is about the same as previously.
CI: https://github.com/adoroszlai/ozone/actions/runs/7829598697
LGTM+1
Thanks @errose28, @Galsza for the review.