Add support for Cosmos SDK.

Token name: `Atom`
Token symbol: `Atom`

Ledger implementation: https://github.com/cosmos/ledger-cosmos
RPC documentation: https://cosmos.network/rpc/#/

Slip44: 118 | 0x80000076 | ATOM | Atom (https://github.com/satoshilabs/slips/blob/master/slip-0044.md)

TODO:
- [x] Bech32 Tendermint address
- [x] Transaction Signing Send/Receive Atom
- [x] Swift/Java code generation
- [x] Tests