Prevent underflow in cumulative fields

[defispartan]

Describe the bug

Due to use of scaled vs realtime balances, some calculations may be inexact for cumulative fields, if this occurs it can result in underflow in some scenarios which can permanently break fields.

In Avalanche V3 market:

{
  reserves(where: {symbol: "DAI.e"}){
    symbol
    totalLiquidity
  }
}