Gas mixer and filter variants

Added three atmospheric trinary device variants:
- Mirrored Gas Filter

   ![](https://i.imgur.com/mwKm1sW.gif)
- Mirrored Gas Mixer

   ![](https://i.imgur.com/361nq3V.gif)
- T-Shape Gas Mixer

   ![](https://i.imgur.com/HYIpxdK.gif)

Added all three to Pipe Dispenser and pipe construction code