Use request->query->get() instead of request->get()

[javiereguiluz]

All the information in EasyAdmin is passed via query parameters. The best way to get the value of these parameters is:

$value = $request->query->get('name');

But most of the time, because I'm lazy, I use the following:

$value = $request->get('name');

This works right, but it's a bit slower and it's not strictly correct in our case (we pass data in the query string, then we shouldn't look for in other parts of the request).

This improvement was suggested by @stof in javiereguiluz@f08250a#commitcomment-9312420

[stof]

For POST requests, it is not exactly the same, because it would read the POST params too