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.

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

Jira Ticket

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

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

Additional details and impacted files

```diff @@ 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