Fate lock code use of byte[] obfuscates the simple data being stored

[keith-turner]

The fate code for locking tables and namespaces is spread across three classes o.a.a.manager.tableOps.Utils, DistributedReadWriteLock, and FateLock. The data for a fate lock consist of two fields the lock type(read or write) and a fate id. Looking at the code and determining it stores these two bits of data is time consuming because the code passes around byte arrays that have that information encoded. If the code be refactored to use concrete types (FateId and DistributedReadWriteLock.LockType) deeper in the code and defer serialization to byte[] till much later in the code then this would make it much easier to understand and maintain the code and keep it correct.