pgsql: Fix set of typos and grammar mistakes

Fix set of typos and grammar mistakes

This is similar to d3bba0415435, batching all the reports of this type
received since the last batch. This covers typos and inconsistencies
for the most part.

The user-visible documentation change impacts only HEAD.

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/b3a95566fc2505d4586680c09d4966dba836cb20

Modified Files
--------------
contrib/pg_stash_advice/stashfuncs.c | 6 +++---
doc/src/sgml/oauth-validators.sgml | 2 +-
doc/src/sgml/stylesheet-html-common.xsl | 2 +-
src/backend/access/transam/xact.c | 16 ++++++++--------
src/backend/access/transam/xlogprefetcher.c | 15 ++++++++-------
src/backend/access/transam/xlogrecovery.c | 2 +-
src/backend/postmaster/startup.c | 4 ++--
src/backend/utils/activity/pgstat_relation.c | 2 +-
src/backend/utils/activity/pgstat_slru.c | 3 ---
src/backend/utils/adt/float.c | 2 +-
src/backend/utils/adt/pg_dependencies.c | 3 +--
src/include/tsearch/ts_type.h | 2 +-
src/port/pqsignal.c | 4 ++--
13 files changed, 30 insertions(+), 33 deletions(-)