Switch to Blockfrost SDK instead of homespun client

[MitchTurner]

https://github.com/blockfrost/blockfrost-rust

It looks like they've improved a lot since I originally looked and it doesn't make sense to maintain our own if that one is perfectly good. I'm not a fan of some of their choices--too many macros, but I don't really want to maintain a client when everyone else is gonna use that client.

[MitchTurner]

NVM. Still missing evaluate endpoint.
blockfrost/blockfrost-rust#29

[vladimirvolek]

Hello!
Please check out our new release https://github.com/blockfrost/blockfrost-rust/releases/tag/v1.0.0 ✨✨✨

Let me know if there is something we can change or improve!

[MitchTurner]

Thanks for the update!