[NET10] Replace the obsolete RunJavaScriptTextInputPanel

[jsuarezruiz]

Description of Change

Replace the obsolete RunJavaScriptTextInputPanel.

Issues Fixed

Fixes #28135

[Copilot]

Pull Request Overview

This PR replaces the obsolete RunJavaScriptTextInputPanel with a new public API method and adds a decrement functionality in the Blazor sample page.

• Replaces the obsolete method with a new signature and updated parameter list in the iOS WebView manager.
• Removes deprecated warning suppression and updates logic for presenting the alert controller.
• Introduces a new Decrement button and corresponding logic in the Blazor sample page with a JavaScript confirmation.

Reviewed Changes

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

File	Description
src/BlazorWebView/src/Maui/iOS/IOSWebViewManager.cs	Replaces obsolete RunJavaScriptTextInputPanel with new ShowJavaScriptTextInputPanel and adjusts alert controller presentation logic.
src/Controls/samples/Controls.Sample/Pages/Blazor/Index.razor	Adds a new Decrement button with confirmation functionality via JSRuntime.

Comments suppressed due to low confidence (1)

src/Controls/samples/Controls.Sample/Pages/Blazor/Index.razor:23

• The new Decrement method with asynchronous confirmation should be accompanied by test cases in TestCases.HostApp and TestCases.Shared.Tests.

async Task Decrement()

[jsuarezruiz]

in .NET iOS we use: https://github.com/dotnet/macios/blob/29de197d989052903d126581cb768f107d256931/src/webkit.cs#L5032
that is using the deprecated method: https://developer.apple.com/documentation/webkit/webuidelegate/webview(_:runjavascripttextinputpanelwithprompt:defaulttext:initiatedby:)

The new way to go is use: https://developer.apple.com/documentation/webkit/wkuidelegate/webview(_:runjavascripttextinputpanelwithprompt:defaulttext:initiatedbyframe:completionhandler:)