Index token balances

[0xekez]

Being able to visualize token balance distributions is super important for transparent governance!

In DAO DAO there are two kinds of token balances:

1. Staked balances which are managed by the cw20-stake contract.
2. Governance token balances which are managed by a cw20-base contract.

I've written an indexer for staked balances (which is largely untested) in the cw20-stake-indexer folder in this repository. We should build an indexer for cw20 balances! It can follow the design for the staked balances indexer, though it is not strictly necessary to include block heights for balances in the index (as those don't matter from the DAO DAO contract's perspective).

The end goal here is to build a data visualization into the UI which will display governance power distribution for a DAO.