Expose Xojo.Introspection to the plugin SDK

For your info, I have submitted a feature request feedback://showreport?report_id=47548, that may or may not be related to another request feedback://showreport?report_id=47502 by Kem Tekinay.

You may also sign up for feedback://showreport?report_id=45158 where I request support for auto data type in plugin SDK.