Enhance Makefiles to rebuild objects on map file changes

Hi Community,

While working on the upgrade from GB18030 to GB18030-2022, I updated two GB18030-related map files. However, rebuilding PostgreSQL did not recompile anything, which led me to discover that the Makefiles under src/backend/utils/mb/conversion_procs were missing dependency rules between NAME.o and the corresponding map files.

This patch adds the necessary dependencies to ensure that when a map file changes, the corresponding .o file is rebuilt accordingly.

I have done tests for every Makefile I changed in a way like:

# make a change to a map file
$ make
# a .o got rebuilt
$ make # make again without map file change
# nothing re-compiled

Chao Li (Evan)
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HighGo Infra. Software Inc.
https://www.highgo.com/