Change camera settings about beamngpy

[tdev]

for example in the Lua code:

      core_camera.setByName(0, "relative")
      core_camera.proxy_Player('setupRelative',
        vec3(0, 0, 1), -- pos
        vec3(0, 0, 0), -- euler rotation
        90 -- FOV
      )

[alessiogambi]

I updated the Lua file inside the scenario as follows, and got what I needed:

     core_camera.setByName(0, "relative")
     core_camera.proxy_Player('setupRelative',
        vec3(-0.5, 2, 0.5), -- pos: more or less in front of the car, on the driver side, slightly above the ground
        vec3(180, 0, 180), -- euler rotation: somehow the default camera is facing backward and flipped upside down
        90 -- FOV
      )

[Palculator]

Added a relative_camera method to set up a camera realtive to the vehicle.