AMM - ONE_WAD_U is never used
The const `ONE_WAD_U` is declared but never used. Avoid re-declaring the same constants in multiple source-units (and unit-test cases) as this will be hard to maintain.\\n```\\nuint256 private constant ONE\\_WAD\\_U = 10\\*\\*18;\\n```\\n
Remove unused code. Import the value from a shared resource. E.g.ONE_WAD is declared multiple times in `LibMathSigned`, `LibMathUnsigned`, `AMM`, hardcoded in checks in `PerpetualGovernance.setGovernanceParameter`, `AMMGovernance.setGovernanceParameter`.
```\\nuint256 private constant ONE\\_WAD\\_U = 10\\*\\*18;\\n```\\n