add "quiet" mode to ocesql (to not output "LIST OF CALLED DB Library API")

[GitMensch]

precompiling a pco without any EXEC SQL leads to:

precompile start: EMPTY.pco
=======================================================
              LIST OF CALLED DB Library API
=======================================================
=======================================================

Using a "normal" source leads to

precompile start: NORMAL.pco
=======================================================
              LIST OF CALLED DB Library API
=======================================================
Generate:OCESQLPrepare
Generate:OCESQLIDExecPrepare
Generate:OCESQLIDConnect
Generate:OCESQLIDExecSelectIntoOne
Generate:OCESQLIDExecSelectIntoOne
Generate:OCESQLIDExecSelectIntoOne
Generate:OCESQLIDExec
Generate:OCESQLIDExecSelectIntoOne
Generate:COMMITuseDBNAME
Generate:ROLLBACKuseDBNAME
=======================================================

This is very verbose (so I'd actually suggest to only output all of those when running with --verbose, but if you want one could use --quiet instead (which otherwise could be used/reserved for "no display, only exit code").

I would give implementing that a try, but would like to have the "ok" to implement it either way up-front.