[crypto] multiple improvements of the code base

[tarakby]

Multiple improvements of the crypto package code base. The improvements are unrelated to each other and small, they were therefore grouped in one PR:

• clean up headers and included files in bls12_381_utils.h
• BLST internally defines bool_t as a C boolean type. The first version of the package C layer used bool_t for simplicity. This PR updates the boolean type to use the C native bool type assuming cgo only supports new C compilers.
• add sanity tests of hardcoded scalar multiplications in G1 and G2, to catch obvious bugs or wrong setup.
• consolidate length constants (G1, G2 and Fr serializations) and their respective roles in BLS signature scheme. Remove all duplicated constants.
• use C macros directly in Go code and remove macro wrappers (since newer versions of cgo allow importing C macros)
• Define new C layer error constants and abstract away BLST errors (BLST_ERROR).
• Update the methods used to map points to G1's complement and G2`s complement by using isogenous mapping (test only tools)
• Update the package and run tests to work with the uncompressed G1 and G2 serializations setup. Although the package only works for one specific setup (compression is default and no dynamic switch of serializations), the objective is to support a dynamic switch in the future so that a user can choose the desired serialization of G1 and G2.
• update returned errors of BLSReconstructThresholdSignature stateless API to match the stateful API errors.

[codecov-commenter]

Codecov Report

Merging #4397 (01b64c5) into feature/blst-based-crypto (33c5e0e) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@                      Coverage Diff                      @@
##           feature/blst-based-crypto    #4397      +/-   ##
=============================================================
- Coverage                      53.71%   53.71%   -0.01%     
=============================================================
  Files                            857      857              
  Lines                          79948    79948              
=============================================================
- Hits                           42943    42941       -2     
- Misses                         33607    33610       +3     
+ Partials                        3398     3397       -1     

Flag	Coverage Δ
unittests	53.71% <ø> (-0.01%)	⬇️

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see 7 files with indirect coverage changes