Stellar - Import addresses or private keys

[olemis]

Feature description

Stellar collection wallets

Is your feature request related to a problem? Please describe. Wallet does not support Stellar collection wallets

Describe the solution you'd like Usability similar to popular Stellar wallets

Additional context

TODO: Find a golang library for Stellar Requires #323

Possible implementation

• [ ] Create Stellar collection wallets (backend)
• [ ] Create Stellar collection wallets (GUI)
• [ ] List Stellar collection wallets
• [ ] Encrypt / decrypt files for collection Stellar wallet
• [ ] Implement core.Wallet interface