[12.x] Adds fromJson() to Collection

[DarkGhostHunter]

What?

Allows a developer to just issue a JSON string and decode it from the Collection class instance throught the fromJson() method. It receives a JSON string and accepts depth and flags parameters to pass down to the json_encode method.

use Illuminate\Support\Collection;

public function something(string $json)
{
    return Collection::fromJson($json);
}

It's left to the developer if the JSON should throw an exception on error (via flag) or not.