Fixes#1202
I had to revert the loader changes that switched from/to as it was causes quite a lot of logistical complexity. Instead of using Loaders, we are setting the type of account (account or contact), and it is being displayed appropriately. There is a very slight deviation from the design, however it is consistent with the design for other transaction previews.
feat: add BalanceValidator
Shows an exclamation icon next to the "from" account when the balance for the requested asset is too low.
This is useful when the user starts the transaction wizard on the TransactionPreview step.
fix: SignTransactionModal - set default focused account when none is found
refactor: move token lookup from QML to nim in the toMessage procedure.
fix: 1:1 tx requests - handle case where token contract is not found (ie sending SNT from mainnet and receiving message on testnet)
feat: error checking for building a token transaction
feat: TransactionPreview - add a validation check that disallows continuation if the selected "from" account has insufficient funds
The problem was that the BigInt lib did not handle decimals at all. `divMod` only let the remainder be what is after the dot. So I created my own divde and multiply methods to move the dot depending on the number of decimals