Resolve SSW-310 (deposit formula simplification)

[rrruko]

Note that this changes rounding for deposits

[Quantumplation]

I think we decided not to implement this one, because it changes the AMM behavior, and RV did a significant amount of vetting of that behavior.

[francolq]

The rounding issue is solved by using "ceil division" (rounded-up):

let give_b = (pool_state.quantity_b.3rd * user_gives_a - 1) / pool_state.quantity_a.3rd + 1

With this formula the AMM behavior should be the same.

However, it is understandable if you decide to preserve the current formulas.

[francolq]

Looks good. It makes sense to use rounding up for the given amount, because in previous version you were rounding down the change.