pgcrypto: Add function to check FIPS mode

 pgcrypto: Add function to check FIPS mode
 
 This adds a SQL callable function for reading and returning the status
 of FIPS configuration of OpenSSL.  If OpenSSL is operating with FIPS
 enabled it will return true, otherwise false.  As this adds a function
 to the SQL file, bump the extension version to 1.4.
 
 Author: Daniel Gustafsson <daniel@yesql.se>
 Reviewed-by: Joe Conway <mail@joeconway.com>
 Discussion: https://postgr.es/m/8f979145-e206-475a-a31b-73c977a4134c@joeconway.com