increase_balance
Adds a certain amount of money to an account. It does NOT update total supply, extra care is needed to either increase it or remove the assets from another account.
Only supposed to be called internally, use functions like mint or transfer whenever possible.
Can only be called from an operation.
Return
the final balance of the account
Parameters
account
the account that should receive the asset increase
asset
the asset that should be given to the account
amount
the amount to give