[sfm] Add new parameters to the SfM process

[servantftransperfect]

• Add a new hard threshold for minimal angle in initial pair selection (The current minimal angle is only heavily reducing the score of the pair with the low angle).
• Triangulation reprojection error (To discard observation for a given triangulated point) is available as a public parameter.
• Triangulation reprojection error is now dependent on the feature scale (the higher the scale, the higher the tolerance) <-- This may create algorithm behavior change !

[CedricThebault]

It would be nice to be able to disable the residual error weighting, but I acknowledge that it would require a lot of changes to expose it up to the node, whereas commenting a single line of code can achieve the same.