Issue when searching with UTF8 strings

[RinneganLSharp]

Theres an error when using the search with characters like ā, ē, č, ū, š, etc... It is because the code uses strtolower instead of mb_strtolower...

It is easily fixed by replacing strtolower function with \Str::lower for example.

[nmkr]

made an pull request, need that too .. thanks :+1:

[EdgarsK]

+1, please merge

[hasanmova]

for fix bug . im find all strtolower function in Bllim\Datatables.php and set mb_strtolower