Prefight check for PHP zlib

[pawsey-kbuckley]

On the back of noticing theese two recent commits

commit d8f876fe59738bca8eac5c145f820fbce0cff3bc
Author: wilpig <[email protected]>
Date:   Mon Jun 26 10:24:24 2023 -0500

    Add another optional preflight check for the ldap module

commit 23f621be0ddd7cc00f07f443c587cd070dd91aa0
Author: wilpig <[email protected]>
Date:   Mon Jun 26 10:08:32 2023 -0500

    Reorganize preflight
    
    relabeled most of the php module checks to make them more obvious that they 
    are looking for php modules.  also moved their positions around so they will 
    be clumped together and added a warning class for modules like zip and curl 
    that we aren't failing on but added notes that functions will break if they
    aren't present

I recalled that a colleague of mine had found that some of the report functionality
didn't work on our instance, because we didn't have the PHP zlib module installed.

I can't see that it is beng checked for in the Preflight, but given that you are flagging
up things that don't make the initial install fail but may impede runtime functionality,
if you think it needs to be, maybe you could add that too.