Support json as a dataType for queueTrigger

#### Repro steps

1. Have a queue trigger
2. Insert a json string into the queue as the message data: `{"hello":"World"}`

#### Expected behavior

Function receives the json as a json object so it can be properly turned into a hashtable for PowerShell Function users

#### Actual behavior

Function receives the json as a string and it gets passed in as a string.

#### Known workarounds

```powershell
param($QueueItem)

$parsedData = $QueueItem | ConvertFrom-Json
```

#### Related information

* Programming language used - `powershell`
* Bindings used - `queueTrigger`