feat: finish pair selection annotation
feat: finish pair selection annotation

Summary: This Diff does what it says.

Reviewed By: fabianschenk

Differential Revision: D30010831

fbshipit-source-id: b67d0f99b656f7795dbf238fe5e940195715e8b5

mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM