Validation Context destroys self destroy before clean up

[nielslyngsoe]

Fix example and make sure super.destroy is handled first. And only trigger the callback with undefined once.

[Copilot]

Pull Request Overview

This PR ensures that the self destroy process in the validation controller triggers the base class destroy routine before performing additional cleanup, and updates observable subscriptions to use the new observe method for consistent reactive handling.

• Moved the call to super.destroy() to the beginning of the destroy() method in the validation controller.
• Replaced direct subscribe calls with this.observe in the validation dashboard for improved subscription management.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/Umbraco.Web.UI.Client/src/packages/core/validation/controllers/validation.controller.ts	Reorders the destroy method to call super.destroy() before performing cleanup, eliminating a duplicate call.
src/Umbraco.Web.UI.Client/examples/validation-context/validation-context-dashboard.ts	Updates observable subscriptions to use this.observe instead of subscribe.

Comments suppressed due to low confidence (1)

src/Umbraco.Web.UI.Client/examples/validation-context/validation-context-dashboard.ts:51

• [nitpick] Verify that using 'this.observe' integrates correctly with your subscription management to ensure proper unsubscription and avoid potential memory leaks.

this.observe(this.validation.messages.messagesOfPathAndDescendant('$.form'), (value) => {