This commit makes the router directives standalone and refactors some of
the Router injectables to be `providedIn: 'root'` along with factory
functions for initialization.

This commit updates the Router itself to be `providedIn: 'root'` with a
factory function rather than provided in the `RouterModule`.

… their providers

`entryComponents` is a feature that is not used or necessary in Angular
anymore.

The provideRoutes function of the Router returns a Provider array and should not be typed as 'any'

The BOOTSTRAP_DONE/bootstrapDone Subject is only used as part of the
`enabledBlocking` initial navigation. Rather than completing the subject
in a common bootstrap listener, this logic can be done in its own
listener as part of the `provideEnabledBlockingInitialNavigation`
function.

The PathLocationStrategy is already provided by default in the factory of LocationStrategy