Added new handled error for when request body is not valid JSON

module/Core/src/Exception/MalformedBodyException.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\Exception;
+
+use Fig\Http\Message\StatusCodeInterface;
+use JsonException;
+use Mezzio\ProblemDetails\Exception\CommonProblemDetailsExceptionTrait;
+use Mezzio\ProblemDetails\Exception\ProblemDetailsExceptionInterface;
+
+use function Shlinkio\Shlink\Core\toProblemDetailsType;
+
+class MalformedBodyException extends InvalidArgumentException implements ProblemDetailsExceptionInterface
+{
+    use CommonProblemDetailsExceptionTrait;
+
+    public static function forInvalidJson(JsonException $prev): self
+    {
+        $e = new self('Provided request does not contain a valid JSON body.', previous: $prev);
+
+        $e->detail = $e->getMessage();
+        $e->title = 'Malformed request body';
+        $e->type = toProblemDetailsType('malformed-request-body');
+        $e->status = StatusCodeInterface::STATUS_BAD_REQUEST;
+
+        return $e;
+    }
+}