Use LinkGenerator instead of UrlHelper to generate URL

[MikeAlhayek]

When we need to generate URL, we typically inject IUrlHelperFactory and IActionContextAccessor to create an instance if IUrlHelper for creating a URL.

When the request comes in from Minimal API or background task, there is no action context available which will throw exceptions. It's better to inject LinkGenerator instead and use the methods to generate Url or Paths as needed.

[Piedone]

This should only be done after we fix #16259.

[Piedone]

Where does this come up, exactly? Where have you seen link generation failing during a minimal API call or a bg task? Since I suppose it's not that we'd want to change all the IUrlHelperFactory usages.

[MikeAlhayek]

I don't recall the details. But if you trigger workflow for example from a minimalAPI and you have workflow that use IUrlHelperFactory it would throw an exception. LinkGenerator is the correct way to generate links. We just have to use extensions that accept HttpContext instance as an argument.