[10.x] Add str()->take($limit) and Str::take($string, $limit)

[moshe-autoleadstar]

Take the first or last {$limit} characters.

Before

str('abcdef')->substr(0, 2) // 'ab'
Str::substr('abcdef', 0, 2); // 'ab'

After

str('abcdef')->take(2) // 'ab'
Str::take('abcdef', 2); // 'ab'