ncpcalls: move Client32 transport helpers out of NCP API file

Move the Client32/Raw5 transport helper routines from c32ncp.c into
ncpcall.c.

This keeps c32ncp.c focused on the ncpXX_YY_* protocol API wrappers in
preparation for the later ncpapi.c/ncpapi.h rename, while ncpcall.c owns the
lower-level requester and Client32 transport helpers.

No packet layout or NCP wrapper behavior is changed.

c32ncp.h

@@ -27,6 +27,14 @@
 
 #ifndef C32NCP_H
 #define C32NCP_H
+
+UI c32_build_handle_path(uint8 *buf, uint8 dhandle,
+                         uint16 dirbase, uint8 style,
+                         int count,
+                         const char *c1, const char *c2, const char *c3);
+UI c32_build_handle_path_from_dos_path(uint8 *buf, uint8 dhandle,
+                                       uint16 dirbase, uint8 style,
+                                       const char *dospath);
 int c32_get_ncp_handle(uint16 *handle_lo, uint16 *handle_hi);