Bug in `denom_metadata` validation

[angelorc]

I've been setting up a new testnet for BitSong and encountered a bug during the validation of the denom_metadata in the genesis file.

To get things running, I had to manually tweak the genesis file as follows:

1. Set .app_state.bank.denom_metadata[0].name to BitSong
2. Set .app_state.bank.denom_metadata[0].symbol to BTSG
3. Reordered .app_state.bank.denom_metadata[0].denom_units to move the entry {...denom:"ubtsg"...} to index 0

I'm not entirely sure if these fixes should be implemented during the import or export phase of setting up the genesis file.

I’m leaving this issue open for further discussion