Add option to encapsulate eXeLearning service requests through a proxy

[erseco]

It would be beneficial to add an option in the Moodle plugin configuration to encapsulate the requests made to the eXeLearning service through a proxy or similar solution. This would prevent the service from being directly exposed, adding an additional layer of security to the integration with external services. Having this functionality would allow administrators to secure their network traffic while maintaining the flexibility of the plugin.