pgsql: Add alternative output for OpenSSL 3 without legacy loaded

Add alternative output for OpenSSL 3 without legacy loaded

OpenSSL 3 introduced the concept of providers to support modularization,
and moved the outdated ciphers to the new legacy provider. In case it's
not loaded in the users openssl.cnf file there will be a lot of regress
test failures, so add alternative outputs covering those.

Also document the need to load the legacy provider in order to use older
ciphers with OpenSSL-enabled pgcrypto.

This will be backpatched to all supported version once there is sufficient
testing in the buildfarm of OpenSSL 3.

Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/FEF81714-D479-4512-839B-C769D2605F8A@yesql.se
Backpatch-through: 9.6

Branch
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REL_11_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/19e91a40bf26530788d1dae39fa3e7e5a52ca7b2

Modified Files
--------------
contrib/pgcrypto/expected/blowfish_1.out           |  95 +++
contrib/pgcrypto/expected/cast5_1.out              |  48 ++
contrib/pgcrypto/expected/des_1.out                |  31 +
contrib/pgcrypto/expected/pgp-decrypt_2.out        | 421 +++++++++++++
contrib/pgcrypto/expected/pgp-pubkey-decrypt_1.out | 652 +++++++++++++++++++++
doc/src/sgml/pgcrypto.sgml                         |   7 +
6 files changed, 1254 insertions(+)