Expose the plugin framework in the managed package

[jongpie]

Currently, the plugin framework is only available in the unlocked package - since managed packages have strict rules about what changes can be made to existing global Apex classes, the framework was intentionally excluded from the managed package to make it easier to change the framework later. The current plugin framework is v2/the second framework implementation, so the original concern with adding it to the managed package was that the framework might need to change again..... but no major changes have been made to the framework in about 2 years, so it seems stable now.

To expose the plugin framework, there are a couple of changes needed:

• Change the Apex class LoggerPlugin to be global
• Change the interfaces LoggerPlugin.Batchable and LoggerPlugin.Triggerable to be global
• Update LoggerPlugin__mdt to change <visibility>Protected</visibility> to <visibility>Public</visibility>

Some test plugins need to then be created that use the managed package to validate that the managed package can, in fact, successfully use the plugin framework.