Currently each mod must register integration handlers provided by the lib, such as:

    this.registerIntegrationHandler(
        "jei",
        "com.codetaylor.mc.athenaeum.integration.jei.IntegrationPluginHandlerJEI"
    );

It would be more convenient if the ModBase class could load and initialize handlers as needed by modules.

A mod should have the ability to register its own integration handlers that would override the default integration handlers provided by the lib.

This could be accomplished by lazy instantiation of the handlers as needed.