[operator-tools] Provide a utility to detect and correct incorrect RegionInfo's in hbase:meta

HBASE-23328 describes a problem in which the serialized RegionInfo in the value of hbase:meta cells have an encoded regionname which doesn't match the encoded region name in the rowkey for that cell.

This problem is normally harmless as assignment only consults the rowkey to get the encoded region name. However, this problem does break other HBCK2 tooling, like extraRegionsInMeta. 

Rather than try to update each tool to account for when this problem may be present, create a new tool which an operator can run to correct meta and then use any subsequent tools as originally intended.