[11.x] Added support for passing custom JSON flags in the http client response factory.

[maxwellmezadre]

Adds support for passing custom JSON flags in the HTTP client response factory. When the body is an array, it is now encoded using the provided JSON flags, which allows developers to preserve specific numeric formatting (e.g. trailing zeros with JSON_PRESERVE_ZERO_FRACTION) when needed.

Before

Http::fake(
    '*' => Http::response(['value' => 10.0])
);

// When making a request:
$response = Http::get('https://example.com');
// The response JSON returns:
// ["value" => 10]

After

Http::fake(
    '*' => Http::response(['value' => 10.0], flags: JSON_PRESERVE_ZERO_FRACTION)
);

// When making a request:
$response = Http::get('https://example.com');
// The response JSON returns:
// ["value" => 10.0]

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!