O3-5061: Enabled and Added Configuration for Bill Waiver

[reshma2004]

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• This PR has a title that briefly describes the work done including a conventional commit type prefix and a Jira ticket number if applicable. See existing PR titles for inspiration.
• My work is based on designs, which are linked or shown either in the Jira ticket or the description below.
• My work includes tests or is validated by existing tests.

Summary

1. Reverted the code to O3-5057 PR to enable Waiver Bill.
2. Remove hard-coded waiver UUID.
3. Modified waiver logic to create negative line items instead of payment records.
4. Add configurable waiverBillableServiceUuid to config schema.
5. Waivers now reduce bill total as line item discounts rather than recorded payments

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[reshma2004]

This branch has continious updates. I did not push the file billable-services/bill-waiver/utils.ts as it has folder missing. It worked properly without getting updated code yesterday. Today it does not work because utils file is removed. I will work further on this PR with latest code.