Unable to use multisearch if jackson json handler is used

[jdvalenzuelah]

Description
When using JacksonJsonHandler with a default ObjectMapper, multisearch throws InvalidDefinitionException when serializing request.
As a work around updating property visibility fixes it.

objectMapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY)

Expected behavior
It should not be needed to change property visibility to make multisearch request

Current behavior
Exception is thrown

Screenshots or Logs

java.lang.RuntimeException: Meilisearch Exception: {com.fasterxml.jackson.databind.exc.InvalidDefinitionException. Error=com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class com.meilisearch.sdk.MultiSearchRequest and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)}
	at com.meilisearch.sdk.http.request.BasicRequest.create(BasicRequest.java:22)
	at com.meilisearch.sdk.HttpClient.post(HttpClient.java:95)
	at com.meilisearch.sdk.Client.multiSearch(Client.java:433)

Environment (please complete the following information):

• OS: macos
• Meilisearch version: 1.9.0
• meilisearch-java version: v.0.14.0