[SDK-1931] Add support for canActivateChild and canLoad in AuthGuard

[stevehobbsdev]

This PR adds support for two other Guard interfaces: CanActivateChild and
CanLoad

• canActivateChild is used on a route definition that contains child routes, to
  determine whether any of those child routes can be accessed
• canLoad is used for lazy-loaded modules to determine whether the module
  should be loaded or not

The playground has been updated with some new links that demonstrate these
scenarios. For canLoad, observe the network trace while authenticated to
see that the JS assets for that module are only loaded when the route is
accessed. When unauthenticated, clicking the link does nothing as the module
should not be loaded. In the real world, canActivate may also be used on
this route to auto-login if it is accessed, but I wanted to test only the
loading part here.

Additionally, canActivateChild necessitates two new components and routes
being added to the playground: /child, and /child/nested. The former should
be accessible anonymously, while the latter (a child route) requires a login
and will auto-login when accessed.

Unit tests available for the new AuthGuard functionality and E2E tests have
been defined to cover the behaviour on the playground.

Note: This PR also updates SPA SDK to 1.12.0. More dependency updates coming in a future PR.

[lbalmaceda]

the others inline the template and remove the styles (empty array). This one looks like the auto-generated one. Let's keep one style on all of them, and remove unnecessary files (e.g. styles, template, etc)