Custom wallet API

[bartolomej]

This PR adds a concept of a "managed account", which is an account whose private keys are known by Flowser.

Managed accounts can be created and used to automatically authorize/send transactions through our new wallet API.

Changes

• Implement a simple wallet API that allows us to:
  • execute transactions without manual authorization by the user (with fcl-dev-wallet we used previously)
  • create new managed accounts that can be used to authorize transactions automatically
• automatically import managed accounts from project's flow.json config
• other improvements & fixes

Wallet API

Create account

This creates a new "managed account" and returns its info.

http POST localhost:6061/api/wallets/accounts

Send a transaction

This will send a transaction given the authorizer/payer/proposer account addresses and Cadence source code.

All the provided account addresses must be "managed accounts".

http POST localhost:6061/api/wallets/accounts/transaction \
  proposerAddress=0x01cf0e2f2f715450 \
  payerAddress=0x01cf0e2f2f715450 \
  authorizerAddresses:='["0x01cf0e2f2f715450"]' \
  cadence='transaction { prepare(signer: AuthAccount) { log(signer.address) } }'

[bartolomej]

Implemented in the scope of onflow/developer-grants#150