Remove trace_recovery_messages

Remove trace_recovery_messages

This GUC was intended as a debugging help in the 9.0 area when hot
standby and streaming replication were being developped, able to offer
more information at LOG level rather than DEBUGn.  There are more tools
available these days that are able to offer rather equivalent
information, like pg_waldump introduced in 9.3.  It is not obvious how
this facility is useful these days, so let's remove it.

Author: Bharath Rupireddy
Discussion: https://postgr.es/m/ZXEXEAUVFrvpquSd@paquier.xyz