FW: fix OAK-D-SR camera enum. IMX296 updates:

- support for RPi GS Cam paired with Luxonis SL6996 RPi camera adapter
- support for external trigger on XTR/XTRIG pin: active low, pulse width determines exposure time. Limitation:
needs an initial trigger shortly after start to avoid a crash, or `DEPTHAI_WATCHDOG=0` can be a workaround

Author: alex-luxonis