Recommendations: update button in My Plan to go to Recommendations

In #12277 and #12429, we added a "checklist" component to the Jetpack dashboard, as well as a CTA that would lead you to the checklist in Calypso.
We never really expanded on that checklist and its display in the React dashboard, but we now have a Recommendations component we use in Jetpack, since #18437.

This commit removes the elements from the checklist that we never used, and updates the CTA link in "My Plan" to point to the new Recommendations, when those recommendations must be shown to site owners.

projects/plugins/jetpack/_inc/client/my-plan/index.jsx

@@ -38,7 +38,7 @@ export function MyPlan( props ) {
 				activeProducts={ props.activeProducts }
 				plan={ sitePlan }
 				purchases={ props.purchases }
-				siteRawUrl={ props.siteRawUrl }
+				siteAdminUrl={ props.siteAdminUrl }
 			/>
 			<MyPlanBody
 				activeFeatures={ activeFeatures }