Update database utility & installment table to have a column for billing period

[adizafri2000]

Currently, when bill statements are calculated and generated, some of the items are actually charges for the previous month while the others are for the current month. For example:

• Electricity, water, unifi are all previous-month charged. This means that for a bill on December 2023, the calculated total for the mentioned items are actually charges for November 2023.
• Sewa (Rent) and washing machine installment are current-month charged. This means that for a bill on December 2023, the calculated total for the mentioned items are for December 2023.

This column is important especially when a resident leaves on the start of a month, it can be confusing to split the bills as we have to remember and find out which items of the bill are previous-month charges and which are current-month charges.

Suggested solution:

1. Update tables to have a new column is_previous_month_charge (or current month) to contain boolean values.
2. Previous-month charges like electricity, water & unifi will have its field set to TRUE while the others set to FALSE.

There is no application or use for this feature in the automation's calculations yet, but for manual checking it is very helpful to have such records.

[adizafri2000]

Added new column is_previous_month_charge in utility table for boolean values