[9.x] Add expects to built-in Facade testing methods

[jasonmccreary]

The built-in testing layer for Facades wraps many underlying Mockery methods which is very great. But it's missing one of the most important testing methods - expects.

Currently shouldReceive is the only out of the box expectation. However, in most cases, shouldReceive does not provide the desired confidence. This can be confusing when new to testing.

In the end, just because something should receive a call, doesn't mean it did. So shouldReceive must included a count modifier such as once, twice, etc to trigger the desired behavior.

Given that it's often the case where you want to ensure something was called, I believe adding expects can help improve the testing experience within Laravel.

Within Mockery expects is simply an alias for shouldRecieve()->once(), yet it's a far more expressive method (which aligns nicely with Laravel), streamlines the code, and avoids the footgun scenario described above.

Before:

Cache::shouldReceive('remember')
        ->with('testing', 'is', 'important')
        ->once();

After:

Cache::expects('remember')
        ->with('testing', 'is', 'important');

[jasonmccreary]

Note: per the discussion in #34932 this is a breaking change.

While likely a low impact, if an underlying Facade object has an expects method, it will no longer be passed through and instead use this concrete expects method. Applications would need to update the name of the underlying method.