Reuse Correct Expense Total Calculation

[JLambertazzo]

fixes #1663

Root Cause:

• "Spent" and "Expenses" values on the budget page are being calculated by different functions

• The value under "Spent" is calculated with budget.actual_spending, which does not include Uncategorized spending

  • in #1663, notice that 62% of the $3007 is missing
  • was able to recreate this locally
    

• This is because Uncategorized category is not present on the budget_categories array in the budget class
  

Proposed Fix:

• Reuse expense_categories_with_totals.total_money which already calculates monthly expense totals, including Uncategorized spending
• Convert Money to amount to stay consistent with expected return type of actual_spending

Alternatively

Could fix by explicit inclusion of uncategorized expenses in actual_spending, but expense_categories_with_totals.total_money already calculates the desired value, and from the issue it seems we do expect the results to be the same, so I implemented the proposal above instead in this PR.

Results

After implementing the fix, the totals are consistent

[zachgoll]

Nice, thanks for tracking this down! I think your chosen solution makes sense here.