Revert "Apply transaction batches in periodic intervals (#4504)" (#4852)

This reverts commit 002893f280.

There were two files with conflicts in the automated revert:

- src/ripple/rpc/impl/RPCHelpers.h and
- src/test/rpc/JSONRPC_test.cpp

Those files were manually resolved.

src/ripple/app/main/Application.cpp

@@ -1533,7 +1533,6 @@ ApplicationImp::start(bool withTimers)
     {
         setSweepTimer();
         setEntropyTimer();
-        m_networkOPs->setBatchApplyTimer();
     }
 
     m_io_latency_sampler.start();