Billing dashboard improvements

The billing dashboard now enables the user to view combined data for All providers.

For the main bar chart, the user can select Grouped or Stacked presentation, and switch currencies. The platform will perform a conversion based on the conversion factor that was configured by the administrator.

The round chart at the top shows a breakdown of the last bill by providers.

After selecting a provider, the user can also display the latest bills broken down by services, for example, virtual machines, storage, networks. The platform uses the categories found in the provider's bills to create the breakdown. The round chart at the top shows the last bill broken down by services.