Fix multiple requests for ItemsProvider when changing the TotalItemCount

[dariatiurina]

Fix multiple requests for ItemsProvider when changing the TotalItemCount

Description

This pull request improves the QuickGrid component by fixing how pagination state is tracked to prevent unnecessary data refreshes, and adds new end-to-end tests and a test component to verify correct ItemsProvider call behavior when filtering. The main focus is on ensuring that applying filters via pagination reset or explicit data refresh does not trigger extra data loads.

Changes:

• Moved the assignment of _lastRefreshedPaginationStateHash in QuickGrid.razor.cs to after the data load completes, ensuring the hash accurately reflects the refreshed state and preventing unnecessary refreshes.
• Added new end-to-end tests in QuickGridTest.cs to verify that filtering with either pagination reset or explicit refresh only results in a single additional ItemsProvider call, preventing redundant refreshes.
• Introduced a new test component, QuickGridFilterComponent.razor, to support these tests by simulating filtering and tracking ItemsProvider calls.

Fixes #62605

[Copilot]

Pull request overview

This pull request fixes a pagination state tracking issue in the QuickGrid component that was causing unnecessary data refreshes when filters changed the TotalItemCount. The fix ensures that the pagination state hash is updated only after data loads complete successfully, preventing premature state tracking that could trigger redundant refresh cycles.

Key changes:

• Moves _lastRefreshedPaginationStateHash assignment to after data load completion in the non-virtualized path
• Adds comprehensive E2E tests to verify single ItemsProvider calls when filtering via pagination reset or explicit refresh
• Introduces a new test component to simulate and verify filtering behavior

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
src/Components/QuickGrid/Microsoft.AspNetCore.Components.QuickGrid/src/QuickGrid.razor.cs	Relocates pagination state hash assignment to occur after successful data load instead of before, fixing double-refresh issue
src/Components/test/testassets/BasicTestApp/QuickGridTest/QuickGridFilterComponent.razor	New test component simulating filter application with call count tracking to validate the fix
src/Components/test/E2ETest/Tests/QuickGridTest.cs	Adds two new test cases verifying single ItemsProvider call for both pagination reset and explicit refresh scenarios
src/Components/test/testassets/BasicTestApp/Index.razor	Registers the new test component in the test app navigation menu