get_underlying_balance in registry return values that are not with the correct decimal precision

[NicolasWent]

Hello,

The issue:
The method: get_underlying_balance from the registry does not give the balances with the right decimal precision

Example:
In polygon on this given registry: https://polygonscan.com/address/0x094d12e5b541784701FD8d65F11fc0598FBC6332#readContract

For the pool: 0x445FE580eF8d70FF569aB36e80c647af338db351

At the time of my writing, here are the reserves that I got from the contract:
0x8f3Cf7ad23Cd3CaDbD9735AFf958023239c6A063 (DAI): 7484982047960936456164609
0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174 (USDC): 10327405276018000000000000
0xc2132D05D31c914a87C6611C10748AEb04B58e8F (USDT): 8072344730218000000000000

USDT has 6 decimals which would mean that the reserve is: 8072344730218000000000000 / 106 = 8072344730218000000 which is way to high.
Instead the real value of the reserve of USDT is: 8072344730218000000000000 / 1018 = 8072344.730218

Which means that the value returned by the method get_underlying_balance for USDT have 18 decimal precision instead of the 6 decimal precision that it should have.