Purpose
=======
Since the account apocalypse in 9.0, there are no way to filter the accounts
based on their 'internal group'.
Specification
=============
Add a Selection field 'internal_group' on the account.account.type to allow
filtering the accounts. The possible internal groups are the following:
- Equity
- Asset
- Liability
- Income
- Expense
Also, set the value to the account types defined in data.
TaskID: 1868221
Nicolas Bayet
cb1aa9c596