fix(governance): add check for strict Multisig threshold validation

[blockchainguyy]

Strict Weighted Multisig threshold validation

This PR adds a check to revert if there are any leftover signatures, when threshold is crossed to make the threshold validation strict.

• add error and check in smart contract for strict validation.
• remove positive test for signatures exceeding required signatures.
• add negative test to revert in case of signatures exceeding required signatures.
• add comment stating operator is an optional param in setup, which can be removed in the future
• remove check for transferring operator role to address 0.

Jira Ticket

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.69%. Comparing base (ddff2f9) to head (082794d).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #177   +/-   ##
=======================================
  Coverage   98.68%   98.69%           
=======================================
  Files          48       48           
  Lines         763      764    +1     
  Branches      160      160           
=======================================
+ Hits          753      754    +1     
  Misses          1        1           
  Partials        9        9           

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[milapsheth]

Rename PR to fix(governance): .. since it's a non breaking fix in the governance contract folder