Hyundai CAN FD Safety: Split TX and RX checks assignments

[sunnyhaibin]

• Split from Hyundai Safety: Cleanup V2 #1965
• Splits TX and RX safety checks into separate sections
• Replaces BUILD_SAFETY_CFG with dedicated SET_TX_MSGS and SET_RX_CHECKS
• No functional changes
• Part of Clean up Hyundai safety and car interface #1942

[sshane]

I worry that this is harder to keep track of because now the if statements are duplicated. The real fix is something like #1800