Feature/hysp clear signing

[Keyur279]

Adding clear signing support for 4 HYSP vault functions on Ethereum mainnet. Each function has a unique 4-byte selector (calculated from keccak256(functionSignature)[0:4]). The firmware reads these selectors from the transaction's data field to identify which function is being called, then parses the arguments and displays human-readable information to the user.
The 4 functions:

1. approve(address,uint256) - Selector: 0x095ea7b3
   • Standard ERC-20 function (not HYSP-specific)
   • Gives a vault permission to spend tokens from user's wallet
   • 2 args: spender address (who can spend), amount (how much they can spend)
   • Used twice: once for USDC→vault, once for mevUSD→vault
2. depositInstant(address,uint256,uint256,bytes32) - Selector: 0xc02dd27a
   • Midas-specific function on Issuance Vault
   • Deposits tokens (USDC/USDT) and receives mevUSD
   • 4 args: tokenIn (which token depositing), amount, minReceive (slippage protection), referrerId (for tracking)
3. redeemInstant(address,uint256,uint256) - Selector: 0x8b53f75e
   • Midas-specific function on Redemption Vault
   • Burns mevUSD and receives tokens back (USDC/USDT) with 0.5% fee
   • 3 args: tokenOut (which token to receive), amount (mevUSD burning), minReceive (slippage protection)
4. redeemRequest(address,uint256) - Selector: 0xbfc2d46a
   • Midas-specific function on Redemption Vault
   • Queued redemption (no fee, ~24-48hr wait)
   • 2 args: tokenOut, amount
     Key contract addresses:

• USDC: 0xa0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 (6 decimals)
• USDT: 0xdAC17F958D2ee523a2206206994597C13D831ec7 (6 decimals)
• mevUSD: 0x548857309BEfb6Fb6F20a9C5A56c9023D892785B (18 decimals)
• Midas Issuance Vault: 0x5455222CCDd32F85C1998f57DC6CF613B4498C2a
• Midas Redemption Vault: 0x9C3743582e8b2d7cCb5e08caF3c9C33780ac446f