refactor: extract useMoneyRequestReportPagination

[sosek108]

Explanation of Change

This is PR 4 of a 10-PR stack decomposing the MoneyRequestReport list components (MoneyRequestReportActionsList / MoneyRequestReportTransactionList) into focused hooks and presentational sub-components (issue #99919, superseding drafts #99307 and #99417).

This slice extracts the pagination behavior into a dedicated hook:

• New: src/components/MoneyRequestReportView/useMoneyRequestReportPagination.ts — owns loading more actions for the money-request report view: the FlashList edge handlers (onStartReached / onEndReached via useLoadReportActions), the auto-load-newer loop with its stalled-cursor guard, and the IOU backfill loop (the backend prioritizes IOU actions for money-request reports, which can leave non-IOU chat messages in a gap that this loop fills by walking getOlderActions backwards from the IOU cursor).
• Edit: src/components/MoneyRequestReportView/MoneyRequestReportActionsList.tsx — replaces the inline useLoadReportActions wiring, the two pagination effects, and the onStartReached/onEndReached callbacks with a single useMoneyRequestReportPagination call. Scroll handling and data derivation stay inline — they are extracted in the next slices of the stack.

Pure refactor — no behavior change.

Stack note: this PR is stacked on #100025 (decompose/money-request-report-transactions-a2), which is stacked on #100024 and #100023. Until those PRs merge, the diff here also shows their commits. Only the "Extract useMoneyRequestReportPagination" commit belongs to this slice.

Fixed Issues

$ #99919
PROPOSAL:

Tests

1. Open an expense report with more than one page of report actions (50+ comments) — verify the transaction table and the comments render as before
2. Scroll to the top of the comments — verify older comments load in as you reach the top
3. Scroll to the bottom — verify newer comments load in as you reach the bottom (open the report via a deep link to an old comment first, so newer actions exist)
4. Open a large money-request report (50+ actions with IOU actions) — verify chat messages between the oldest loaded message and the newest ones backfill automatically after the report loads
5. Switch to another report and back — verify pagination starts fresh (cursors reset) and the report loads correctly
6. Run npx jest tests/ui/MoneyRequestReportActionsListRejectModalTest.tsx and verify it passes

• Verify that no errors appear in the JS console

Offline tests

1. Go offline and scroll to the edges of the loaded comments — verify no request loops occur and the list stays stable
2. Go back online — verify loading older/newer comments resumes working

QA Steps

Same as Tests.

• Verify that no errors appear in the JS console

PR Author Checklist

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I added steps for the expected offline behavior in the Offline steps section
  • I added steps for Staging and/or Production testing in the QA steps section
  • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
  • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability).
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I followed proper code patterns (see Reviewing the code)
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• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I followed the guidelines as stated in the Review Guidelines
• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
• If a new CSS style is added I verified that:
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  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(theme.componentBG))
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• If the PR modifies code that runs when editing or sending messages, I tested and verified there is no unexpected behavior for all supported markdown - URLs, single line code, code blocks, quotes, headings, bold, strikethrough, and italic.
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• I added unit tests for any new feature or bug fix in this PR to help automatically prevent regressions in this user flow.
• If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.

Screenshots/Videos

Android: Native

Android: mWeb Chrome

iOS: Native

iOS: mWeb Safari

MacOS: Chrome / Safari

[codecov]

Codecov Report

✅ Changes either increased or maintained existing code coverage, great job!

Files with missing lines	Coverage Δ
...equestReportView/MoneyRequestReportActionsList.tsx	83.01% <100.00%> (+22.70%)	⬆️
...estReportView/MoneyRequestReportEmptyStateView.tsx	100.00% <100.00%> (ø)
src/hooks/useMarkAsRead.ts	95.94% <100.00%> (+0.05%)	⬆️
src/hooks/useUnreadMarker.ts	94.44% <100.00%> (+0.15%)	⬆️
...tReportView/useMoneyRequestReportVisibleActions.ts	52.63% <52.63%> (ø)
...questReportView/useMoneyRequestReportPagination.ts	69.04% <69.04%> (ø)
... and 34 files with indirect coverage changes