[Feat.] Support for General stats endpoints

[DiFronzo]

Add stats calls for different blockchains. For more information see this page.

On the following:

• Stats on multiple blockchains at once
• Bitcoin-like blockchain stats
• Ethereum-like blockchain stats
• Ripple-like blockchain stats
• Stellar-like blockchain stats
• Monero-like blockchain stats
• Cardano-like blockchain stats
• Mixin-like DAG stats
• Tezos-like blockchain stats
• EOS-like blockchain stats
• Cross-chain token stats
• Omni Layer stats
• ERC-20 stats

[thevibhu]

Can I take up this issue?

[DiFronzo]

@thevibhu Sure. If you have any questions or inquiries add it to this issue.

[thevibhu]

Like I checked "ERC-20" has its own file for stats calls and including other code. Do I have to follow the same code flow? A file for each stat and one for all the stats? After I am done, how can I test my code?