Support style: explode

[lmazuel]

Need m4 fix: https://github.com/Azure/autorest.modelerfour/issues/314
Need azure-core: Azure/azure-sdk-for-python#12410
Will fix: Azure/autorest.testserver#197

If style explode, instead of generating something like:

query_parameters['arrayQuery'] = self._serialize.query("array_query", array_query, '[str]', div=',')

We want to generate

query_parameters['arrayQuery'] = [self._serialize.query("array_query", q, 'str') for q in array_query]

Need testserver test: Azure/autorest.testserver#199

[lmazuel]

autorest 5.1.0-preveiw8