ADD: Allow extra attributes to table columns

[bernhardh]

This pull request is to allow extra attributes - especially classes - to table columns.

Usecase: If you link a column with url method right now, nothing shows you, that the cell is linked (except the cursor). With this commit you can style it like a link:

Tables\Columns\TextColumn::make("owner.name")
    ->withAttributes(["class" => "text-green-500"])
    ->url(fn ($record): string => route("...")),

[danharrin]

Thanks! I had to add the extraAttributes() method to columns.