Feature/patch token decimals into voucher hub

[Le-Caignec]

• Add commentary regarding the Halborn audit report, mentioning informational feedback about the updateVoucherTypeDuration function.
• Override the decimals function of ERC-20 to set the token's decimal precision to 9, aligning with RLC standards.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.30%. Comparing base (145178d) to head (c9ee780).
Report is 14 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop      #50   +/-   ##
========================================
  Coverage    99.29%   99.30%           
========================================
  Files            4        4           
  Lines          284      286    +2     
  Branches        53       53           
========================================
+ Hits           282      284    +2     
  Misses           2        2           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[gfournieriExec]

Thanks, I'll let the team re-check