Reorganization of expect(), amGoingTo(), comment(), wantTo() #6146

Currently, there are 4 "comment" methods that all do (almost) the same:

So I'm suggesting to drop the first 3 in favor of comment(). Reasons:

• The term comment is self-explanatory in the sense that it gives you a hint where/how this will be displayed. amGoingTo and expectTo are non-saying.
• Having 3 methods just for prefixing the comment with 2, 3, or 4 single words (e.g. "I expect") is ridiculous. If you want the exact same output, you can do $I->comment('I expect foo');
• "expect" is easily confused with "assert", see wantTo() is not documented #6076 (comment)

And then there's wantTo() which is inconsistently displayed when called multiple times:

$I->wantTo('foo');
$I->wantTo('bar');

... leads to:

✔ AppCest: Bar (0.04s)

App\Tests.functional Tests (1) -----------------------------------------------------------------------------------------------------------------------------------------------------------------
AppCest: Foo

Having some way to add a comment to the test overview output is very handy. But wantTo is semantically the wrong term for it; and the $I-> syntax leads to unanswerable questions when called multiple times.
Suggestions? Maybe an annotation above the function instead of a method within the function?

This would resolve #6076 and #6075