Incident::getListOfIncidents handles query incorrectly

[stephanvierkant]

I'd like to fetch incidents using the API, but the method handles the query parameters incorrectly.

    $this->api->getListOfIncidents([
        'start' => 0,
        'page_size' => 10,
        'category.id' => {foo},
    ])

This doesn't filter the category field, because Topdesk handles this in a weird way: FIQL instead of normal HTTP params. So it should be ?category.id=={foo}.

See https://developers.topdesk.com/tutorial.html#query

[marnickmenting]

@stephanvierkant Can you make a pull request for this?