Ever noticed how much typing stuff over and over again sucks?

Remove the need for Method::Signatures, and also endless repetition of $c->stash->{'scenario'} with two handy localized subs.

```perl
Given "my step", sub {
    # Before
    my $c = shift;
    $c->stash->{'scenario'}->{'mything'} = $c->data;

    # After
    S->{'mything'} = C->data;
}
```

I went and did the digest steps as an example.

Thoughts?