Single-pass totals computation for Trial Balance Excel (Totaling accounts)

[mynjj]

Summary

The query-based Trial Balance Excel report (codeunit 4410 "Trial Balance") synthesized Total/End-Total rows by looping over every Total account and, for each one, re-filtering the buffer and CalcSums-ing once per distinct (Dimension 1, Dimension 2, Business Unit) combination. On charts of accounts with many totals this is O(totals × combinations) passes over the buffer and dominated the cost of large trial balances.

This change computes all totals in a single sweep:

• BuildAccountToTotalsMap maps each posting account to the list of totals whose Totaling range contains it.
• DistributePostingRowsToTotals sweeps the posting rows once, accumulating each row into every containing total's in-memory buffer (keyed by account + dimensions + business unit + period).
• MergeTotalsIntoBuffer runs the budget comparison / all-zero checks and inserts the resulting totals.

Because the map is built only from posting accounts, a parent End-Total whose range spans a nested child End-Total's number no longer re-sums the child's already-inserted buffer row — fixing a latent double-counting bug for nested totals.

Fixes AB#638251

Test plan

• New QueryPathDoesNotDoubleCountNestedTotals verifies a parent End-Total spanning a nested child End-Total counts the underlying posting amount once
• Existing Trial Balance Excel test suite green locally