[BUG] Precision Issue in calculate_propotional_apy Function

[AtelyPham]

We have identified a precision issue in the calculate_propotional_apy function within the rewards.rs file. The function currently uses the Percent type for calculations, which leads to unexpected results due to its whole number representation.

Problem

When calculating the proportional APY, multiplying two Percent values (e.g., 10% and 2%) results in 0% due to rounding down to the nearest whole percentage. This is causing inaccuracies in the APY calculations.

Steps to Reproduce:

1. Call the calculate_propotional_apy function with total_deposit and deposit_cap such that the propotion is 10%.
2. Use an original_apy of 2%.
3. Observe that the resulting APY is 0%.

Expected Behavior:

The function should return a more precise APY value, reflecting the actual multiplication result (e.g., 0.2%).

Impact

This issue affects the accuracy of APY calculations, potentially leading to incorrect reward distributions.

Screenshot

Screenshots of the test I conducted to verify the results of the calculate_proportional_apy function.