[Modules] Add a functionality to check for installed PHP extensions if a module depends on a particular PHP extension

[andygrunwald]

Expected Behavior

Some Modules (like NOC or Downloads) require (or work best) when a particular PHP extension is installed:

• NOC -> Needs ext-snmp
• Downloads -> Suggests ext-ftp

It would be great to add a functionality to the module structure to mark PHP extensions as

• required
• optional

during installation and prevent activation of the module, once the required extensions are not available on the system.

Current Behavior

All dependencies are suggested in the global PHP composer file

Possible Solution

Add such a functionality to modules

Context

• See move ext-ftp and ext-snmp to suggested packages #1098
• Search or extension_loaded in the codebase

[M4LuZ]

FYI - Some Ideas for an improved module management (including dependency management) were already collected here
https://github.com/lansuite/lansuite/wiki/Module-Handling---Requirements
Updated that now with some fresh inspirations