pgsql: Revert pg_get_role_ddl(), pg_get_tablespace_ddl(), and pg_get_da

Revert pg_get_role_ddl(), pg_get_tablespace_ddl(), and pg_get_database_ddl().

List of commits reverted:

4881981f920 Add infrastructure for pg_get_*_ddl functions
76e514ebb4b Add pg_get_role_ddl() function
b99fd9fd7f3 Add pg_get_tablespace_ddl() function
a4f774cf1c7 Add pg_get_database_ddl() function
6c7bce28c83 Fixups for a4f774cf1c7
1f108fc02ec Fix pfree crash in pg_get_role_ddl() and pg_get_database_ddl().
cda0c4c5d6f Reject invalid databases in pg_get_database_ddl()
79fba6ebaba doc: Fix missing role attribute in pg_get_tablespace_ddl() description.
c529ee38b9e Convert ddlutils regression tests to TAP tests.
df1bac400fb Fix timezone dependence in test_misc/012_ddlutils.pl
5642a0367c2 Avoid SIGSEGV in pg_get_database_ddl() on NULL tablespace
2af70e93747 Fix incorrect declarations of variadic pg_get_*_ddl() functions.
d6ed87d1989 Use named boolean parameters for pg_get_*_ddl option arguments

plus the corresponding release notes entries.

Discussion: https://postgr.es/m/20260827015242.54.noahmisch@microsoft.com

Branch
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REL_19_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/db169985c10f02fa6d97920b0fafdde0ade3fde8

Modified Files
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doc/src/sgml/func/func-info.sgml | 118 ----
doc/src/sgml/release-19.sgml | 36 -
src/backend/utils/adt/ddlutils.c | 977 ---------------------------
src/backend/utils/adt/meson.build | 1 -
src/backend/utils/adt/ruleutils.c | 4 +-
src/include/catalog/catversion.h | 2 +-
src/include/catalog/pg_proc.dat | 22 -
src/include/utils/ruleutils.h | 1 -
src/test/modules/test_misc/meson.build | 1 -
src/test/modules/test_misc/t/012_ddlutils.pl | 341 ----------
10 files changed, 3 insertions(+), 1500 deletions(-)