[zk-token-sdk] Restrict a single-bit of 256-bit batched range proof to 128

[samkim-crypto]

Problem

The problem is shared with https://github.com/solana-labs/solana/pull/34747.

Summary of Changes

Restrict the bit-length in a 256-bit range proof to 128.

This is a follow-up to https://github.com/solana-labs/solana/pull/34747. Since this part of the logic is gated, it does not need to be backported.

Fixes #

[codecov[bot]]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (9edf65b) 81.8% compared to head (2abf398) 81.8%. Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #34803     +/-   ##
=========================================
- Coverage    81.8%    81.8%   -0.1%     
=========================================
  Files         825      825             
  Lines      223160   223166      +6     
=========================================
- Hits       182559   182553      -6     
- Misses      40601    40613     +12