Missing clawback and set trust line flags operations

[quietbits]

Hello Ledger Team,

The following operations are missing (throw an error when signing with Ledger):

• Set Trustline Flags,
• Clawback,
• Clawback Claimable Balance.

We tried them on Stellar Laboratory and got the below error. It would be great if these could be added.

Related issue: https://github.com/LedgerHQ/app-stellar/issues/12.