This is the c/c part of MDEV-32102.

Since 5.7, a new capability CLIENT_DEPRECATE_EOF permit to remove some EOF and change resulset ending packet to an OK_Packet with 0xfe header. This permit to save some bytes, and session tracking that is only supported on OK_Packet.

The problem is that the resultset intermediate contains interesting pieces of information in status_flags like SERVER_MORE_RESULTS_EXIST, SERVER_PS_OUT_PARAMS. C/C didn't implement CLIENT_DEPRECATE_EOF due to that.

This will permit C/C support for CLIENT_DEPRECATE_EOF if MARIADB_CLIENT_SEND_INTERMEDIATE_EOF is set too.
This change will permit to support other fix, like MDEV-31560