Improve simple string generator method

[realodix]

The random string generator method is very slow, so the simpleString method (up to 10x faster) was created to reduce the use of the random string generator method.

But the method is too simple. Only 2 unique strings can be generated by the simpleString method, all others must use the random string generator method.

// Only 2 unique strings

['ravel', 'https://github.com/laravel/laravel'],
['ravel', 'https://stackoverflow.com/questions/tagged/laravel'],
['ravel', 'https://www.youtube.com/hashtag/laravel'],
['ravel', 'https://www.reddit.com/r/laravel/'],
['ravel', 'https://dev.to/t/laravel'],
['ravel', 'https://laracasts.com/topics/laravel'],
['ravel', 'https://laravel.io/forum/tags/laravel'],
['ravel', 'https://medium.com/tag/laravel'],
['ravel', 'https://fontawesome.com/icons/laravel'],

['ravel', 'https://en.wikipedia.org/wiki/Laravel'],
['ravel', 'https://id.wikipedia.org/wiki/Laravel'],

['ework', 'https://github.com/topics/framework'],
['ework', 'https://github.com/laravel/framework'],
['ework', 'https://github.com/codeigniter4/framework'],
['ework', 'https://github.com/spring-projects/spring-framework'],
['ework', 'https://github.com/ionic-team/ionic-framework'],

With this PR, we can further reduce the usage of random string generator.

['glvel', 'https://github.com/laravel/laravel'],
['sqdel', 'https://stackoverflow.com/questions/tagged/laravel'],
['yhvel', 'https://www.youtube.com/hashtag/laravel'],
['rrvel', 'https://www.reddit.com/r/laravel/'],
['dtvel', 'https://dev.to/t/laravel'],
['ltvel', 'https://laracasts.com/topics/laravel'],
['lfsel', 'https://laravel.io/forum/tags/laravel'],
['mtvel', 'https://medium.com/tag/laravel'],
['fivel', 'https://fontawesome.com/icons/laravel'],

['ewvel', 'https://en.wikipedia.org/wiki/Laravel'],
['iwvel', 'https://id.wikipedia.org/wiki/Laravel'],

['gtork', 'https://github.com/topics/framework'],
['glork', 'https://github.com/laravel/framework'],
['gcork', 'https://github.com/codeigniter4/framework'],
['gsork', 'https://github.com/spring-projects/spring-framework'],
['giork', 'https://github.com/ionic-team/ionic-framework'],