Murisi/ledger v0.30.2

[murisi]

Updated the Ledger app to partially support Namada v0.30.2. Everything but IBC, InitProposal, and Bridge Pool Transfer transactions is working. More specifically, the following changes have been made:

• Updated the parsing and signing test vectors to be those generated by Namada v0.30.2
• Added support for the new avatar field in become validator
• Added support for denominated amounts in transaction fees in the header
• Added support for parsing transaction memo hashes in the header
• Broadened the set of transaction timestamps that can be printed
• Added support for update steward commission, redelegate, reactivate validator, deactivate validator, resign steward, change consensus key, claim rewards, and change validator metadata transactions
• Support parsing (but not signing) secp256k1 keys in more places in transactions
• Now support parsing and printing transaction memos
• Increased the level of detail displayed in init proposal transactions
• Now include the memo section hash in the wrapper signature

[ftheirs]

Covered by: #29 and #31