pgsql: Improve several permission-related error messages.

Improve several permission-related error messages.

Mainly move some detail from errmsg to errdetail, remove explicit
mention of superuser where appropriate, since that is implied in most
permission checks, and make messages more uniform.

Author: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Discussion: https://www.postgresql.org/message-id/20230316234701.GA903298@nathanxps13

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/de4d456b406bf502341ef526710d3f764b41e2c8

Modified Files
--------------
contrib/file_fdw/expected/file_fdw.out | 3 +-
contrib/file_fdw/file_fdw.c | 10 +-
contrib/test_decoding/expected/permissions.out | 12 +-
src/backend/backup/basebackup_server.c | 4 +-
src/backend/catalog/objectaddress.c | 16 +-
src/backend/commands/copy.c | 12 +-
src/backend/commands/user.c | 167 ++++++++++++++++-----
src/backend/replication/slot.c | 4 +-
src/backend/storage/ipc/procarray.c | 4 +-
src/backend/storage/ipc/signalfuncs.c | 16 +-
src/backend/tcop/utility.c | 5 +-
src/backend/utils/init/postinit.c | 10 +-
src/backend/utils/misc/guc.c | 15 +-
.../dummy_seclabel/expected/dummy_seclabel.out | 3 +-
.../modules/unsafe_tests/expected/rolenames.out | 3 +-
src/test/regress/expected/create_role.out | 80 ++++++----
src/test/regress/expected/dependency.out | 4 +
src/test/regress/expected/privileges.out | 23 ++-
18 files changed, 282 insertions(+), 109 deletions(-)