Supply & Borrow stables adjustments

Here are the changes in this proposal:

• HOLLAR: Borrow cap raised from 5 million to 6 million.
• USDT and USDC: Optimal utilisation increased from 70% to 80%.
• HUSDT: Supply cap doubled from 4 million to 8 million. Rewards increased by 50%.
• HUSDS: Supply cap doubled from 2 million to 4 million. Rewards increased by 50%.
• HUSDe: Supply cap doubled from 2 million to 4 million. Rewards increased by 50%.
• wstETH: Price feed updated.