Add possibility to invert Area series filled area

[kirchet]

Is your feature request related to a problem? Please describe.

Add possibility to fill top area instead of bottom

Describe the solution you'd like

Add an addtional option like invertFilledArea to AreaStyleOptions.

https://github.com/tradingview/lightweight-charts/blob/f28f8112c43f6cc1f0a953dc5dd5ec335af4b39b/src/model/series-options.ts#L210-L287