Add Rabby wallet support

[donnyquixotic]

Overview

Rabby is gaining support as a MetaMask alternative and supports Telos EVM mainnet out of the box. Integration should be low effort (see 'solution' link for more info). We should add it as another login option.

Links

https://rabby.io/
https://github.com/RabbyHub/Rabby#solution

Acceptance Criteria

• User should be able to select 'Rabby' as a login option and complete transactions on mainnet and testnet

Tasks

• Injected provider auth support (if necessary)
• Rabby login button
• Add testnet functionality

Additional Notes

• There is a desktop client in beta for mac and windows
• Mobile app is in development
• https://github.com/RabbyHub/Rabby#potential-issues
• Testnet is not supported out of box, will need to explore solution or possibly reach out to the Rabby team to get our testnet added