Added experimental ticker events

[justinpolygon]

Added the stocks ticker events experimental endpoint.

Running something like this:

// Stocks Ticker Events (experimental)
// https://polygon.io/docs/stocks/get_vx_reference_tickers__id__events
fun stocksTickerEvents(polygonClient: PolygonRestClient) {
    println("META events:")
    polygonClient.experimentalClient.getTickerEventsBlocking(TickerEventsParameters(id = "META")).pp()
}

Will print this:

TickerEventsResponse(
  Companion = Companion(
  )
  status = "OK"
  requestID = "4c65f82386fd8a8e4c4a5065cf27eabb"
  results = TickerEvents(
    Companion = Companion(
    )
    name = "Meta Platforms, Inc. Class A Common Stock"
    compositeFigi = "BBG000MM2P62"
    cik = "0001326801"
    events = [
               TickerEvent(
                 Companion = Companion(
                 )
                 tickerChange = TickerChange(
                   Companion = Companion(
                   )
                   ticker = "META"
                 )
                 type = "ticker_change"
                 date = "2022-06-09"
               ),
               TickerEvent(
                 Companion = Companion(
                 )
                 tickerChange = TickerChange(
                   Companion = Companion(
                   )
                   ticker = "FB"
                 )
                 type = "ticker_change"
                 date = "2012-05-18"
               )
             ]
  )
)