Index events emitted when setting and disabling custom fee for users

[smol-ninja]

The following events are emitted when setting/disabling custom fee for users:

/// @notice Emitted when the admin or the fee manager disables the custom USD fee for the provided user.
event DisableCustomFeeUSD(
    Protocol indexed protocol, address caller, address indexed user, uint256 previousMinFeeUSD, uint256 newMinFeeUSD
);

/// @notice Emitted when the admin or the fee manager sets the custom USD fee for the provided user.
event SetCustomFeeUSD(
    Protocol indexed protocol, address caller, address indexed user, uint256 previousMinFeeUSD, uint256 newMinFeeUSD
);