Obsolete things broken in migrations refactor (#13658)

* Obsolete chings changed in v13

* Fix tests

* Obsolete Execute and add ExecutePlan with default implementation.

This just calls the old implementation and creates an ExecutedMigrationPlan from the result

In V13 this has its own implementation.

* Mention notification in obsolete message

src/Umbraco.Infrastructure/Migrations/IMigrationPlanExecutor.cs

@@ -4,5 +4,12 @@ namespace Umbraco.Cms.Core.Migrations;
 
 public interface IMigrationPlanExecutor
 {
+    [Obsolete("Use ExecutePlan instead.")]
     string Execute(MigrationPlan plan, string fromState);
+
+    ExecutedMigrationPlan ExecutePlan(MigrationPlan plan, string fromState)
+    {
+        var state = Execute(plan, fromState);
+        return new ExecutedMigrationPlan(plan, fromState, state);
+    }
 }