[Sub-org] Improve overview viewer

### Describe the problem

1. Sub-org balance only includes first children, which is misleading for overall balance.
2. You could be hiding money in a org that is 3 levels down, and the only way to know is to open up the tree.

### Describe the feature/solution (optional)

We fix this with 2 definitions,
1. Balance = The amount of money this org has.
2. Sub-org balance = The amount of money this org's sub-orgs, all the way down the tree, have, rolled up.

Implementation wise:
1. Make sub-org balance roll-up sub-orgs and all children.
2. Add a column to the sub-org table, showing sub-org balance for each org that is part of the sub-org tree.