Steps to reproduce
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1. On a bank payment method, enable "Identify Customer".
2. Create a lot of orders paid with this method and invoice them (the customer reporting the issue had 2081 orders).
3. Close the session.

The close takes several minutes, and on a remote database the request is killed by the worker time limit before it completes.

Cause
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`_reconcile_account_move_lines` reconciles each group of lines with its own `reconcile()` call, one per payment. Every call creates its partials and triggers the recompute cascade of the ORM, which searches `account.move.line` over the whole set of payments of the session, so the cost of a single call grows with the number of payments.

`_create_invoice_receivable_lines` has the same shape: the values are grouped per payment, so every group holds a single value and the lines are created one `create()` call at a time.

opw-6242303 already batched the creation and the posting of the split bank payments, and the reconciliation of their receivable lines, but only for the orders that are not invoiced. Invoiced orders go through `split_inv_payment_receivable_lines`, which was left untouched.

Fix
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Gather every reconciliation of the session into a single `_reconcile_plan` call. The entries of the plan are processed independently and in order, so the result is the same as reconciling them one by one, but the recompute cascade runs once instead of once per payment.

Create all the invoice receivable lines in a single `create()` call and dispatch the records back to their payment method or payment afterwards.

Benchmark
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Closing a session of 2081 invoiced orders on a copy of the customer database:
- before: 558s
- after: 54s

opw-6458271

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