Test enabling all coins

It would be great if the concept of enabling/disabling coins is completely hidden from the users.

We should test enabling all coins (in Electrum mode) by default and giving the user an option in advanced settings to switch between Electrum or full node.

This may result in excessive memory use and be unfeasible. In that case we might be able to get clever and enable all coins on startup, check the balance and then disable them.

Alternatively we could implement balance checking completely on our end with Electrum and just query `marketmaker` for the address to check. Although this could lead to inconsistencies between what `marketmaker` thinks the balance is and what our code thinks the balance is. (e.g if one is connected to a more up to date electrum node than the other)