Fix AcceptedAtRoute link generation and add tests

[JamesNK]

Fixes #46722

Previously AcceptedAtRoute was calling GetUriByAddress, and the address was the route name. This is basically the same as the GetUriByName extension method (see below) and searches for an endpoint by the endpoint name instead of the route name.

aspnetcore/src/Http/Routing/src/LinkGeneratorEndpointNameAddressExtensions.cs

Lines 151 to 208 in bb3f0d6

	/// <summary>
	/// Generates an absolute URI based on the provided values.
	/// </summary>
	/// <param name="generator">The <see cref="LinkGenerator"/>.</param>
	/// <param name="httpContext">The <see cref="HttpContext"/> associated with the current request.</param>
	/// <param name="endpointName">The endpoint name. Used to resolve endpoints.</param>
	/// <param name="values">The route values. Used to expand parameters in the route template. Optional.</param>
	/// <param name="scheme">
	/// The URI scheme, applied to the resulting URI. Optional. If not provided, the value of <see cref="HttpRequest.Scheme"/> will be used.
	/// </param>
	/// <param name="host">
	/// The URI host/authority, applied to the resulting URI. Optional. If not provided, the value <see cref="HttpRequest.Host"/> will be used.
	/// See the remarks section for details about the security implications of the <paramref name="host"/>.
	/// </param>
	/// <param name="pathBase">
	/// An optional URI path base. Prepended to the path in the resulting URI. If not provided, the value of <see cref="HttpRequest.PathBase"/> will be used.
	/// </param>
	/// <param name="fragment">An optional URI fragment. Appended to the resulting URI.</param>
	/// <param name="options">
	/// An optional <see cref="LinkOptions"/>. Settings on provided object override the settings with matching
	/// names from <c>RouteOptions</c>.
	/// </param>
	/// <returns>A URI with an absolute path, or <c>null</c>.</returns>
	/// <remarks>
	/// <para>
	/// The value of <paramref name="host" /> should be a trusted value. Relying on the value of the current request
	/// can allow untrusted input to influence the resulting URI unless the <c>Host</c> header has been validated.
	/// See the deployment documentation for instructions on how to properly validate the <c>Host</c> header in
	/// your deployment environment.
	/// </para>
	/// </remarks>
	[RequiresUnreferencedCode(RouteValueDictionaryTrimmerWarning.Warning)]
	public static string? GetUriByName(
	this LinkGenerator generator,
	HttpContext httpContext,
	string endpointName,
	object? values,
	string? scheme = default,
	HostString? host = default,
	PathString? pathBase = default,
	FragmentString fragment = default,
	LinkOptions? options = default)
	{
	ArgumentNullException.ThrowIfNull(generator);
	ArgumentNullException.ThrowIfNull(httpContext);
	ArgumentNullException.ThrowIfNull(endpointName);
	return generator.GetUriByAddress<string>(
	httpContext,
	endpointName,
	new RouteValueDictionary(values),
	ambientValues: null,
	scheme,
	host,
	pathBase,
	fragment,
	options);
	}