Adds RequestVariablesToRequestFacadeRector rule

[peterfox]

Changes

• Adds RequestVariablesToRequestFacadeRector rule
• Adds tests
• Updates Docs

Why

Provides a nice transition from vanilla PHP to Laravel code.

-$_GET['value'];
-$_POST['value'];
-$_GET['value']['sub_value'];
+\Illuminate\Support\Facades\Request::input('value');
+\Illuminate\Support\Facades\Request::input('value');
+\Illuminate\Support\Facades\Request::input('value.sub_value');