[pangea] migrate wallet

[florianlenz]

Feature / Issue

Since we are moving all data over to pangea, we have to move the wallet as well. The wallet is quite a complex thing since we are supporting multiple assets.

A persisted asset might have this (or a similar) data structure:

• symbol (string)
• name (string)
• icon (persisted as byte)
• decimals uint
• addresses key value mapping between network and address
• balances mapping between network an balance. Balance should always be the smallest possible unit.

Acceptance criteria

• tests
• structure that support:
  • tokens
  • currencies
  • different network types (test net etc)
• call module to refresh the balance of an asset
• call module to fetch all tokens
• ui api call to notify pangea about balance changes
• call module to transfer an asset to a given address

Dependencies

• [pangea] dynamic call module #86

[florianlenz]

@kevowevo this should be done at the 30th