pg: Initial support for receiving binary results

Just the initial framework stuff and a few types to test with.

FU.xs

@@ -11,6 +11,7 @@
 #include "c/jsonfmt.c"
 #include "c/jsonparse.c"
 #include "c/libpq.h"
+#include "c/pgtypes.c"
 #include "c/pgconn.c"
 
 
@@ -139,6 +140,11 @@ void q(fupg_txn c, SV *sv, ...)
 
 MODULE = FU   PACKAGE = FU::PG::st
 
+void text_results(fupg_st *st, ...)
+  CODE:
+    st->text_results = items == 1 || SvTRUE(ST(1));
+    XSRETURN(1);
+
 void params(fupg_st *st)
   CODE:
     FUPG_ST_COOKIE;