Aleks+murisi/upgrade v0.22.0

[murisi]

Made changes to the Ledger app to support Namada v0.22.0 (with multisig adjustments). More specifically, we did the following:

• Upgraded the signature section format to one that allows multiple signatures over a set of hashes and made corresponding changes to how signature sections are hashed
• Modified the Ledger app's response to include the set of section indices signed over, because the Namada web interface requires this information to construct a valid signature section
• Implemented a parser for signature sections so that the wrapper signature can sign over these as well (under the condition that its hashes have already been validated). This turned out to be most straightforward way to achieve multisig.
• Upgraded the parsers of the various transaction types in order to be compatible with Namada v0.22.0. Introduced a new transaction type called Unjail Validator during this process. Partially merged in IBC support from the ibc_support branch.
• Updated parsing and signing test vectors and WASM code hashes.