augmented factor

[Xinghy98]

https://github.com/zju3dv/RLP_VIO/blob/master/pvio/src/pvio/estimation/ceres/augmented_plane_distance_error_cost.h#L94 Hello, I compared the code with PVIO, and I found nothing changed in BA factor. I have a problem that when x= -ATAinv*ATb, the input distance should be negative, equal to -parameters[keypoints.size() * 2 + 1][0].