pgsql: Rename SetSingleFuncCall() to InitMaterializedSRF()

Rename SetSingleFuncCall() to InitMaterializedSRF()

Per discussion, the existing routine name able to initialize a SRF
function with materialize mode is unpopular, so rename it.  Equally, the
flags of this function are renamed, as of:
- SRF_SINGLE_USE_EXPECTED -> MAT_SRF_USE_EXPECTED_DESC
- SRF_SINGLE_BLESS -> MAT_SRF_BLESS
The previous function and flags introduced in 9e98583 are kept around
for compatibility purposes, so as any extension code already compiled
with v15 continues to work as-is.  The declarations introduced here for
compatibility will be removed from HEAD in a follow-up commit.

The new names have been suggested by Andres Freund and Melanie
Plageman.

Discussion: https://postgr.es/m/20221013194820.ciktb2sbbpw7cljm@awork3.anarazel.de
Backpatch-through: 15

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/a19e5cee635dc94c9c6e44c8863b4b770920a04b

Modified Files
--------------
contrib/amcheck/verify_heapam.c                    |  2 +-
contrib/dblink/dblink.c                            |  2 +-
contrib/pageinspect/brinfuncs.c                    |  2 +-
contrib/pageinspect/gistfuncs.c                    |  4 ++--
contrib/pg_stat_statements/pg_stat_statements.c    |  2 +-
contrib/pg_walinspect/pg_walinspect.c              |  4 ++--
contrib/pgrowlocks/pgrowlocks.c                    |  2 +-
contrib/postgres_fdw/connection.c                  |  2 +-
contrib/xml2/xpath.c                               |  2 +-
src/backend/access/transam/rmgr.c                  |  2 +-
src/backend/access/transam/xlogprefetcher.c        |  2 +-
src/backend/commands/event_trigger.c               |  4 ++--
src/backend/commands/extension.c                   |  6 +++---
src/backend/commands/prepare.c                     |  2 +-
src/backend/foreign/foreign.c                      |  2 +-
src/backend/replication/logical/launcher.c         |  2 +-
src/backend/replication/logical/logicalfuncs.c     |  2 +-
src/backend/replication/logical/origin.c           |  2 +-
src/backend/replication/slotfuncs.c                |  2 +-
src/backend/replication/walsender.c                |  2 +-
src/backend/storage/ipc/shmem.c                    |  2 +-
src/backend/utils/adt/datetime.c                   |  2 +-
src/backend/utils/adt/genfile.c                    |  4 ++--
src/backend/utils/adt/hbafuncs.c                   |  4 ++--
src/backend/utils/adt/jsonfuncs.c                  |  9 ++++-----
src/backend/utils/adt/mcxtfuncs.c                  |  2 +-
src/backend/utils/adt/misc.c                       |  2 +-
src/backend/utils/adt/pgstatfuncs.c                |  6 +++---
src/backend/utils/adt/varlena.c                    |  2 +-
src/backend/utils/fmgr/README                      |  2 +-
src/backend/utils/fmgr/funcapi.c                   | 23 +++++++++++++++-------
src/backend/utils/misc/guc_funcs.c                 |  2 +-
src/backend/utils/misc/pg_config.c                 |  2 +-
src/backend/utils/mmgr/portalmem.c                 |  2 +-
src/include/funcapi.h                              | 14 +++++++++----
.../modules/test_ddl_deparse/test_ddl_deparse.c    |  2 +-
36 files changed, 72 insertions(+), 58 deletions(-)