Add support for Minnet/Testnet networks

[bartolomej]

At least for now, we think about Flowser as being primarily a dev tool for local development - optimized for inspecting and interacting the local emulator network, as we believe Flowser is a unique tool in this area.

But Flowser could as well act as a Devnet/Testnet explorer. In fact we were already thinking that once we make the local development experience good enough, we could start optimizing for alternative use cases.

Fun fact: in the past we actually did support Testnet/Mainnet, but later decided to remove it temporarily to focus on local development use-case.

Upvote this discussion if you'd adding support for mainnet/testnet networks helpful.

[bartolomej]

Few thoughts/ideas:

• We designed Flowser with extensibility and portability in mind from the start (with platform-independant architecture - could be run either as a web or a desktop app)
• We could run the Flowser's backend in the cloud and allow clients (Flowser desktop app or even potential future web apps) to connect to it and retrieve data from Testnet/Mainnet networks
• A possible future direction is to establish Flowser as an end-to-end GUI tool for developing, deploying, monitoring and maintaining dapps on Flow