HBASE-30169 Split completed parent region added to RIT list on host RS and master crash

[Umeshkumar9414]

• Bug: When a host RegionServer and master crashes, regionCrashed() blindly added all hosted regions to RIT, including split-completed parent regions that should never be reassigned.
  • Fix: Added isSplitOrMerged() guard in regionCrashed() to skip split/merged regions. Extracted isSplitOrMerged() and isReplica() helpers to reduce duplication with handleRegionStateNodeOperation().
  • Removed broken isRegionInTransition(RegionInfo) API — RegionInfo.COMPARATOR considers offline/split flags, so lookups failed when those flags differed between the query and stored instance. Replaced
    with encoded-name-based lookup in test utility.
  • Added test testRITWithSplitTableRegion — splits a region, crashes the hosting RS, restarts the master, and verifies the split parent is NOT in the RIT list.