Sync with GingerLib: new fb/vbSM + changes to CS debugging

[DanieleDiBenedetto]

Need to sync with the most recent changes to ginger-lib:

• Introduced Hopwood optimized vbSM gadget ginger-lib#126 and Hopwood Optimized Fixed-Base Scalar Multiplication ginger-lib#129, which affects the SchnorrSignature gadget; no manual edit needed, just a ginger-lib dependency update (it's a circuit change though, so whenever this modification is imported into the SDK, pk and vk needs to be regenerated);
• Refactor constraint system ginger-lib#131, which removes TestConstraintSystem. Must fix only the corresponding UT of the NativeThresholdSignature circuit, and sync again the depencies to ginger-lib and marlin.

[DanieleDiBenedetto]

Will automatically close when merging #70