Replace deprecated log_connections values in docs and tests

Replace deprecated log_connections values in docs and tests

9219093cab2607f modularized log_connections output to allow more
granular control over which aspects of connection establishment are
logged. It converted the boolean log_connections GUC into a list of strings
and deprecated previously supported boolean-like values on, off, true,
false, 1, 0, yes, and no. Those values still work, but they are
supported mainly for backwards compatability. As such, documented
examples of log_connections should not use these deprecated values.

Update references in the docs to deprecated log_connections values. Many
of the tests use log_connections. This commit also updates the tests to
use the new values of log_connections. In some of the tests, the updated
log_connections value covers a narrower set of aspects (e.g. the
'authentication' aspect in the tests in src/test/authentication and the
'receipt' aspect in src/test/postmaster). In other cases, the new value
for log_connections is a superset of the previous included aspects (e.g.
'all' in src/test/kerberos/t/001_auth.pl).

Reported-by: Peter Eisentraut <peter@eisentraut.org>
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Discussion: https://postgr.es/m/e1586594-3b69-4aea-87ce-73a7488cdc97%40eisentraut.org