[Tracking] Refactor MoneyRequestConfirmationListFooter to reduce re-renders

[Julesssss]

Sub-tracking issue for #81849. Splits a large refactor into 4 PRs that narrow Onyx subscriptions and extract sections in the Create Expense confirmation step:

Original comment here with more details.

• Refactor: extract sections from MoneyRequestConfirmationListFooter #90208
• perf: narrow Onyx subs in InvoiceSenderField and ReportField #90311
• Narrow confirmation leaves with selectors #90321
• refactor: add ConfirmationFieldsProvider and grouped types #90325

Then:

two short follow-ups:

• Narrow usePolicyForTransaction orchestrator - unscoped policy collection subscription for a per-key one.
• Migrate ReportField to read its own slice — drop the transaction prop workaround threaded, replacing it with the useTransactionSelector hook introduced in PR 3. Removes the last piece of prop drilling in the footer.

Issue Owner

Current Issue Owner: @ShridharGoel

[Julesssss]

Looks like we can make a start on reviews for the first two PRs that are open, I'll assign you now @ShridharGoel

[OlimpiaZurek]

Update: Resolved conflicts and addressed reviewer comments. Both PRs are ready for further review. Once they are merged, I will rebase and proceed with the 3rd one.