[5.8] Validate container alias registration

[seriquynh]

The Container::getAlias() method currently throws LogicException. This exception is forwarded to many other container methods that call getAlias() and there are a lot of conflicts with the container interface.

• \Illuminate\Container\Container::when() >>> breaks container interface.
• \Illuminate\Container\Container::resolved() >>> breaks container interface.
• \Illuminate\Container\Container::addContextualBinding() >>> breaks container interface
• \Illuminate\Container\Container::extend() >>> breaks container interface
• \Illuminate\Container\Container::rebinding()
• \Illuminate\Container\Container::resolve()
• \Illuminate\Container\Container::resolving() >>> breaks container interface
• \Illuminate\Container\Container::afterResolving() >>> breaks container interface
• \Illuminate\Container\Container::getExtenders()
• \Illuminate\Container\Container::forgetExtenders()

Let's validate container alias registration to avoid these conflicts. And I think it's reasonable to add @throws \LogicException to \Illuminate\Contracts\Container\Container::alias(). Each class has to implement this logic.

[imanghafoori1]

Maybe the message at this phase should be changed into a more meaningful one.
like:

"[{$abstract}] cannot be aliased to itself.

[seriquynh]

This message is fine now and I just focus on the idea. I think if this is accepted, you or someone can change the message.

[imanghafoori1]

Taylor usually makes these modifications himself after merging. I just mention them, as a note.
Hoshimi's son.

[seriquynh]

I know. So, let him decide. Thanks!

[driesvints]

I agree with this change but we should definitely document this in the upgrade guide.