Fix NavigationManager.Refresh ignoring forceReload parameter

[ManuelEnzo]

Problem

NavigationManager.Refresh(bool forceReload = false) always performed a full
forced page reload, regardless of the forceReload argument passed in:

public virtual void Refresh(bool forceReload = false)
    => NavigateTo(Uri, forceLoad: true, replace: true);

The forceReload parameter was accepted but never used — forceLoad: true
was hardcoded. This contradicts the method's own doc comment, which states
that when forceReload is false the response may be merged with the
existing document to preserve client-side state (enhanced navigation),
falling back to a full reload only if necessary.

This affects any NavigationManager that relies on the base class's default
Refresh implementation (e.g. HttpNavigationManager, used for
non-interactive/static server-side rendering) rather than overriding it.
RemoteNavigationManager (Blazor Server) and WebAssemblyNavigationManager
already forward forceReload correctly through their own overrides, so this
does not affect interactive Blazor Server/WebAssembly circuits.

Fix

Pass forceReload through to NavigateTo's forceLoad option instead of
hardcoding true:

public virtual void Refresh(bool forceReload = false)
    => NavigateTo(Uri, forceLoad: forceReload, replace: true);

Testing

Added three regression tests in NavigationManagerTest.cs covering
Refresh(false), Refresh(true), and the default parameter value, asserting
the ForceLoad option passed to NavigateTo matches the argument.

Ran the full Microsoft.AspNetCore.Components.Tests suite
(eng\build.cmd -test -projects .\src\Components\Components\test\Microsoft.AspNetCore.Components.Tests.csproj):
1278 tests, 1265 passed, 5 failed, 8 skipped. The 5 failures are pre-existing
on a clean checkout of main (unrelated EventCallbackFactoryBinderExtensionsTest
date-formatting tests and one PersistentServicesRegistryTest test, likely
culture-dependent) and are unaffected by this change — confirmed by running
the same suite before applying the fix.

Fixes #59854

[dotnet-policy-service]

Thanks for your PR, @ManuelEnzo. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[ManuelEnzo]

@dotnet-policy-service agree

[ManuelEnzo]

@dotnet-policy-service agree