[tracking] Key generation readiness

[cwgoes]

dependencies:

• ledger (HW wallet) keys integration #70
• New genesis flow #2088
• Some interface work presumably, but I didn't find any issue for it /cc @jurevans @mateuszjasiuk @emccorson - We are moving to SDK key generation in Implement the usage of Namada SDK for Account derivation namada-interface#182 - this is assigned to @mateuszjasiuk NOTE Ledger can already generate keys via the extension, any maintenance would simply be to update dependencies as they change
• Ledger (hardware wallet) updates #2025 by @murisi (ditto, please link/make an issue)
• Cross-test HD key derivation between Ledger device, Namada extension, and SDK implementation #2067

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This issue tracks feature-completeness of key generation. Key generation is feature-complete if and only if:

• Users can generate keys using the Namada CLI (which should use the same code as the SDK uses - DRY)
  • Manually (random mnemonic)
  • Using the Ledger hardware wallet
• Users can generate keys using the Namada interface
  • Manually (random mnemonic)
  • Using the Ledger hardware wallet
• Users can use these keys to generate appropriate signatures as required for genesis transactions and afterwards
• We're confident that key generation is secure and final (no further changes)
• All key generation-related code is tested, believed to be complete, and audited by at least two people other than the author

Please add any dependencies that you believe are necessary to meet these requirements in the list above.

related: #1950