Functional guards and resolvers were introduced in the Angular router in v14.2.
This commit adds the ability to generate functional router guards by
specifying `--guardType` instead of `--implements`. These guards are also
accompanied by a test that includes a helper function for executing the
guard in the `TestBed` environment so that any `inject` calls in the
guard will work properly. Functional resolvers are generated by adding
the `--functional` flag.
