Generate initial accounts for project

[bartolomej]

Problem

Flow cli's flow init command initialises a configuration with one default account (so called "service account"). This initial account is needed, so that a user is even able to generate new accounts or send transactions.

We currently don't expose service account details (this account creation is also not logged in transaction events), therefore flowser user has no way to actually create new accounts or send transactions if he creates a project with managed flow emulator.

Solution

We should generate initial accounts (or just use the service account) and expose their private details to the user (private key).