fixed real_interest_cost calculation

- missing -1
- r=n((A/P)^(1/nt)) -> r=n((A/P)^(1/nt)-1)
Updated output table row lables

- "Total loan cost including interest:" -> "Total cost including interest ($):"
- "Total loan interest ($)" -> "Effective interest cost ($)"
- "Real interest rate" -> "Effective APR (%)"

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Display effective APR for bank loan

- populated Effective APR row of Bank row of output table