[stacked] support ledger cosmos signing in staking-cli

[mkaczanowski]

TL;DR

This PR:

1. fixes the ledger cosmos signing - the newest app is no longer compatible with the official ledgerhq lib, instead I had to switch to the repo maintained by the author of the ledger hw app
2. added support for signer-ledger-cosmos to staking-cli
3. Fixed the issue when the public key is not returned by LCD (doesn't have to be)

Test plan

$ npm run staking-cli -- cosmos tx delegate 0.15 -c ./config.testnet.json -s ledger -b
Check TX status here: https://testnet.celestia.explorers.guru/transaction/7EB07E30FAEF5AAB3F9E1283CCE24F553B795342A875357B27C8A504AC3D19BC

[welldan97]

Looks good!