Lack of input parameter validation for amount parameters

The Points and Vault contracts lack input validation for several parameters, specifically ensuring that amount-related parameters (such as token amounts, fees, and rates) are within valid ranges. This oversight can lead to minor operational inefficiencies, unnecessary gas costs, and potential logical inconsistencies.

While the immediate impact of this lack of input validation is relatively low, it can lead to several issues:

1. Operational Inefficiencies: Unchecked zero amounts can result in unnecessary transactions, consuming extra gas without performing meaningful operations.
2. Minor Logical Inconsistencies: Functions performing actions with zero amounts might lead to minor inconsistencies or state changes that do not align with the intended logic.
3. Usability Concerns: Incorrect fees or rates, if not validated, can make the contract less user-friendly or cause unexpected behaviors that may confuse users.

Implement input validation for these parameters to ensure they are different than zero.

if (amount == 0) revert("Amount should be different than zero");