* fix: rounding adjustment in apply_discount_amount taxes_and_totals
* refactor: minor changes
* fix: set the rounding difference while calculating tax total in the last tax row and add test case
* fix: failing test case
* fix: made changes in get_total_for_discount_amount in taxes_and_totals
* fix: failing test cases
* fix: changes as per review
* refactor: remove unnecessary use of flt
* refactor: improve logic
* refactor: minor change
* refactor: minor changes
* fix: add a test case for applying discount with previous row total in taxes
* fix: failing test case
* refactor: flatter code, remove `flt` usage for accuracy
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Co-authored-by: Sagar Vora <sagar@resilient.tech>