ASI 2.0

[thewhaleking]

Major release that breaks from old API compatibility.

Will include:

• proper SS58 decoding
• one single encoder/decoder (currently use py-scale-codec and bt-decode)
• Abandon ScaleObj in favour of the cyscale.ScaleType, but improved with the typing of ScaleObj
• ????

Tracking branch: https://github.com/opentensor/async-substrate-interface/tree/release/2.0.0

Bittensor/btcli tests will be skipped until their equivalents have been created/updated