Fix the sliding cookie configuration when using frontend tests

[Erwinvandervalk]

What issue does this PR address?
The sliding cookie tests were still in the 'old' testing style.

Turns out that the new frontend style of wiring things wasn't working for sliding cookies. So now the tests explicitly run the 'old' and the 'new' style of wiring things up. This will likely be the pattern I'll use for future tests also, because I want to make sure you can still use V3 style (explicit auth wireup) and v4 style (automatic wireup)

Also, it turns out that, if you do AddScheme, aspnet core also adds a specific post configuration middleware:

https://github.com/dotnet/aspnetcore/blob/main/src/Security/Authentication/Core/src/AuthenticationBuilder.cs#L52

We have to do the same in our dynamic scheme wireup. (basically, it only adds the timeprovider, but still, quite important)

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[Copilot]

Pull Request Overview

This PR fixes the sliding cookie configuration when using frontend tests, ensuring compatibility between the legacy (V3) and new (V4) configuration styles. It introduces explicit wiring of the TimeProvider in tests and production code, supports both manual and frontend-managed BFF setups via parameterized tests, and adjusts cookie configuration events for sliding expiration.

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
bff/test/Bff.Tests/TestInfra/TestHost.cs	Adds TimeProvider to the DI container for testing purposes.
bff/test/Bff.Tests/TestInfra/TestDataBuilder.cs	Introduces a helper method for generating UserSessionsFilter for tests.
bff/test/Bff.Tests/TestInfra/TestData.cs	Provides a FakeTimeProvider instance and current time accessor.
bff/test/Bff.Tests/TestInfra/BffTestBase.cs	Implements a new parameterized test configuration with BFF setup type options.
bff/test/Bff.Tests/SessionManagement/CookieSlidingTests.cs	Updates cookie sliding tests to run with both V3 and V4 setup configurations and refines clock advancing logic.
bff/src/Bff/SessionManagement/Configuration/PostConfigureSlidingExpirationCheck.cs	Adjusts the cookie sliding expiration configuration to check multiple scheme types.
bff/src/Bff/SessionManagement/Configuration/PostConfigureApplicationCookieTicketStore.cs	Applies similar scheme checking logic for the application cookie ticket store.
bff/src/Bff/DynamicFrontends/BffConfigureOpenIdConnectOptions.cs	Injects and assigns the TimeProvider to OpenIdConnect options.
bff/src/Bff/DynamicFrontends/BffConfigureCookieOptions.cs	Injects and assigns the TimeProvider to Cookie options.
bff/src/Bff/BffBuilder.cs	Minor cleanup in the builder class.