FINERACT-2640: Extend FeignLoanHelper charge and disbursal methods

[DeathGun44]

Description

Extends the RestAssured → Feign migration (PR 4 of the roadmap) to Loan Charge Management, Loan State Transitions, and Disbursement Details.

Key Changes

Added Loan Charge Management to FeignLoanHelper: 11 pure-Feign methods covering the full charge lifecycle on a loan — addLoanCharge, getLoanCharges, getLoanCharge, updateLoanCharge, deleteLoanCharge, getLoanChargeTemplate, waiveLoanCharge, payLoanCharge, adjustLoanCharge, plus convenience overloads addSpecifiedDueDateCharge and addDisbursementCharge.

Extended Loan State Transitions: Added the remaining state-transition methods — closeLoan, closeAsRescheduled, forecloseLoan, assignLoanOfficer, unassignLoanOfficer, and recoverGuarantee — routing correctly between LoansApi (state commands) and LoanTransactionsApi (transactional commands).

Added Disbursement Detail & Available Amount Methods: addAndDeleteDisbursementDetail, getDisbursementDetail, updateDisbursementDate, and modifyAvailableDisbursementAmount covering multi-tranche disbursement workflows.

Added Reschedule Methods: createRescheduleRequest, approveRescheduleRequest, and the convenience composite createAndApproveRescheduleRequest via RescheduleLoansApi.

Extended LoanRequestBuilders: Static typed factories for all new operations — rejectLoan, withdrawLoan, closeLoan, forecloseLoan, assignLoanOfficer, unassignLoanOfficer, addLoanCharge (with and without due date), waiveLoanCharge, payLoanCharge, adjustLoanCharge.

Updated FeignLoanTestBase: Exposed delegate methods for all new FeignLoanHelper and FeignChargesHelper capabilities, keeping test classes thin and consistent with the base pattern.

Checklist

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[DeathGun44]

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