Proposal of dynamically adjusting minting fees and add a lock-up period of six weeks to the YOU Unifying Staking Pool

1、dynamically adjusting minting fees equals six weeks YOU rewards (uUSD and uBTC vaults)
The current fix minting fee rate is 1.5625% which is rather high. The APR of YOU rewards is changed all the time, when the APR is low, lower minting fees will attractive users to mint more,which help the YOU price going up and help the APR of YOU rewards going up as well.

2、add a lock-up period of six weeks for the YOU Unifying Staking Pool after withdawing
Holding YOU is different from holding uAssets because holding YOU means joining the DAO community and participating in governance, which is a long-term action. This new feature will deny short-term speculators to deposit YOU into the unifying staking pool just in order to gain revenue. They will choose selling it or providing liquidity which will help the TVL of swapping pool and help the APR of YOU Unifying Staking Pool as well.