New callsites for message browser

[AlexisCnockaert]

• I passed the method browser API to SystemNavigationso the new tabs for the method browser work well

[jecisc]

For this one maybe we should discuss. I already talked with Alexis about that. Maybe it's not the best fix because we have a hidden cyclic dependency.

I talked with Guille and he suggested that we update Spec so that it does not use the system navigation to implement the commands but leave a way to configure the commands execution. Then, when the MethodBrowser is loaded, it could tell the code presenter to use it to browser the senders/implementors/references...

[guillep]

The system navigation is not an issue.
Actually, since the presenter is configured with a system navigation, we can change the system navigation by another implementation which is nice.

Now, here the system navigation implements a kind of "callback façade".
The issue here is that in this case, the callback methods were refactored to add a new argument.
So we should think: what are the navigation callbacks that the code presenter should expose, and what is the minimal set of arguments that should be passed/exposed.

I think passing the presenter itself is very flexible.
Then, newtools can define its own callback that receives the code presenter and does its magic.