[deprecated] Deprecate AssertCountWithZeroToAssertEmptyRector to improve test readability with more explicit methods

[TomasVotruba]

Ref: #456 (comment)

I'm looking into this rule once again, as it actually creates less readable code. We ignore it completely on couple of projects.
empty() is too vague structure and PHPStan and Rector rules try to refactor away form it.

Also in $this->assertCount(x, ...) is more readable in context of similar counter tests:

$this->assertCount(1, ...);
$this->assertCount(5, ...);
$this->assertCount(0, ...);

Saying that, I'll deprecate and remove this rule form the set, to promote higher quality code 👍