pgsql: Add TAP tests for timeouts

Add TAP tests for timeouts

This commit adds new tests to verify that transaction_timeout,
idle_session_timeout, and idle_in_transaction_session_timeout work as expected.
We introduce new injection points in before throwing a timeout FATAL error
and check these injection points are reached.

Discussion: https://postgr.es/m/CAAhFRxiQsRs2Eq5kCo9nXE3HTugsAAJdSQSmxncivebAxdmBjQ%40mail.gmail.com
Author: Andrey Borodin
Reviewed-by: Alexander Korotkov

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/eeefd4280f6e5167d70efabb89586b7d38922d95

Modified Files
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src/backend/tcop/postgres.c                  |  10 +++
src/test/modules/test_misc/Makefile          |   4 +
src/test/modules/test_misc/meson.build       |   4 +
src/test/modules/test_misc/t/005_timeouts.pl | 129 +++++++++++++++++++++++++++
4 files changed, 147 insertions(+)