Handles top-level JSON Arrays from XML:choice with multiple occurs

When using the XML pattern complexType+choice you can define
an array of records, even though it would not be technically possible
in XML.

Example of an array of 3 records:
```
<xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema'>
 <xs:element name='root'>
   <xs:complexType>
     <xs:choice maxOccurs='3'>
       <xs:element name='s' type='xs:string'/>
       <xs:element name='i' type='xs:int'/>
     </xs:choice>
   </xs:complexType>
 </xs:element>
</xs:schema>
```
Translates the XML
```
<root>
  
mystring

  <i>1</i>
  <i>2</i>
</root>
```

Into:
```
[{"s": “mystring”}, {"i": 1}, {"i": 2}]
```