This change removes the IActionContextAccessor as a dependency of
UrlHelper, and shifts UrlHelper to use a factory pattern. Consumers of
IUrlHelper should create an instance using the factory when needed.
This is the last part of MVC that has a dependency on IActionContext
accessor. As part of this change we no longer register it by default, and
treat it as an optional component.
- remove useless `configuration` variables and `Configuration` instances
- remove "Review" code comment
- unintentionally included in commit 4b5dd19
- reduce repeated code in `TestHelper` for functional tests
- `CreateServer()` methods had duplicate code, an ambiguous match, and an odd order
- rename `GetTestConfiguration()` to `UseCultureReplacer()` in functional tests