Bug fix: cohesive price formatting on invoices

When adding a new billable item or product to an invoice, the way the values dispayed under “Total” were inconsistent—billable items displayed with a decimal (i.e. $0.00) and products displayed without one (i.e. simply $0). Below is an example of what it looked like:

We’re fans of consistency, so we changed this, and it will always display with a decimal now!