Add TitleCreator / PageCreator

In preparation of #398 
In case `$createFromText( ... )->findRedirect()->getTitle()` is used `findRedirect` as public access point will throw an exception for when $this->pageCreator is `null`.It allows do either `new TitleCreator` or `new TitleCreator( new PageCreator) )` depending on whether I want Redirect resolving or not.

> Why did you make it optional?

Sometimes I just want to have a title using `$createFromText( ... )->getTitle()` without the need for a `PageCreator` instance.