pgsql: Add test module for Custom WAL Resource Manager feature.

Add test module for Custom WAL Resource Manager feature.

Author: Bharath Rupireddy, Jeff Davis
Discussion: https://postgr.es/m/CALj2ACVTBNA1wfVCsikfhygAbZe6kFY8Oz6PhOyhHyA4vAGouA%40mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ae168c794f09984d8fe44e7da2ca6ad3eeb570f1

Modified Files
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doc/src/sgml/custom-rmgr.sgml                      |   7 ++
src/test/modules/Makefile                          |   1 +
src/test/modules/meson.build                       |   1 +
src/test/modules/test_custom_rmgrs/.gitignore      |   4 +
src/test/modules/test_custom_rmgrs/Makefile        |  24 ++++
src/test/modules/test_custom_rmgrs/meson.build     |  34 +++++
src/test/modules/test_custom_rmgrs/t/001_basic.pl  |  61 +++++++++
.../test_custom_rmgrs/test_custom_rmgrs--1.0.sql   |  16 +++
.../modules/test_custom_rmgrs/test_custom_rmgrs.c  | 139 +++++++++++++++++++++
.../test_custom_rmgrs/test_custom_rmgrs.control    |   4 +
10 files changed, 291 insertions(+)