Deprecate unprefixed manual entries for openssl commands

Deprecate unprefixed manual entries for openssl commands

Initially, the manual page entry for the 'openssl cmd' command used
to be available at 'cmd(1)'. Later, the aliases 'openssl-cmd(1)' was
introduced, which made it easier to group the openssl commands using
the 'apropos(1)' command or the shell's tab completion.

In order to reduce cluttering of the global manual page namespace,
the manual page entries without the 'openssl-' prefix have been
deprecated in OpenSSL 3.0 and will be removed in OpenSSL 4.0.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9666)