feat(devnet): add `cw20-ics20` to genesis (#168)

Implements #166.

@hussein-aitlahcen, note that the contract is instantiated with the
following message:
```
{ "default_timeout": 99999999, "gov_contract": "union1jk9psyhvgkrt2cumz8eytll2244m2nnz4yt2g2", "allowlist": [] } 
```

`gov_contract` is the dev account's address, lmk if we need to modify
anything.