message: add core to iplugin
diff: @@ -84,4 +84,11 @@ export interface IPlugin {
  * Plugin version (available in data.properties.version in common schema)
  */
  readonly version?: string;
  +
  + /**
  + * The App Insights core to use for backward compatibility.
  + * Therefore the interface will be able to access the core without needing to cast to "any".
  + * [optional] any 3rd party plugins which are already implementing this interface don't fail to compile.
  + */
  + core?: IAppInsightsCore
  }
  