[Symfony 6] Retrieving a non-string value from "Symfony\Component\HttpFoundation\InputBag::get()" is deprecated

Problem/Motivation

When upgrading to Symfony 5.4 various tests throw deprecation warnings:

Since symfony/http-foundation 5.1: Passing a non-scalar value as 2nd argument to "Symfony\Component\HttpFoundation\InputBag::get()" is deprecated, pass a scalar or null instead.
Since symfony/http-foundation 5.1: Retrieving a non-string value from "Symfony\Component\HttpFoundation\InputBag::get()" is deprecated, and will throw a "Symfony\Component\HttpFoundation\Exception\BadRequestException" exception in Symfony 6.0, use "Symfony\Component\HttpFoundation\InputBag::all($key)" instead.

In #3162016: [Symfony 6] Retrieving a non-string value from "Symfony\Component\HttpFoundation\InputBag::get()" is deprecated we first approached this problem but then the first solution was rolled back, a simpler solution was implemented, but the remainder of the changes were not committed in that issue.

Steps to reproduce

Proposed resolution

Reuse code from #3162016: [Symfony 6] Retrieving a non-string value from "Symfony\Component\HttpFoundation\InputBag::get()" is deprecated that was not committed.

Use $request->query->all(...) when retrieving an array.

Use $request->query->get(...) when retrieving a scalar.

Use $request->query->all()[...] when retrieving either an array or scalar and the subsequent code can handle both types.

Where the query isn't guaranteed to be set, start using $request->query->has().

User interface changes

no

API changes

no

Data model changes

no

Release notes snippet

no