feat(email-service): add Error Report tab with delivery failure analysis

[ornokreans]

Summary

Adds an Error Report tab to the Email Service widget that provides delivery failure analysis for the current project, giving operators a quick overview of what is failing and why without having to sift through individual mail log entries.

Changes Made

• New ErrorReport component (ErrorReport.tsx) — full-page report view with summary stat cards, a day-range selector (persisted to localStorage), and interactive bar-chart rankings that filter a detail table on click.
• New Error Report tab in AppContent.tsx — inserted between Setup and Maillog; tab selection is synced to the URL hash (#error-report) for deep-linking.
• New reportDataFn + useGetReportData hook — fetches /v1/report via the existing API infrastructure and exposes typed response interfaces (Report, RankingList, ReportSearchResponse, etc.) in actions.ts / queries.ts.
• Generified fetchFromAPI — refactored to fetchFromAPI<T> so it can be reused for both mail-search and report endpoints without duplicating response-handling logic; removed now-redundant checkStatus helper.
• Minor fixes — added tag[] filter field to MailSearchOptions, added response field to MailLogEntry, and added enabled prop to useGetData to support conditional queries.

Related Issues

• Issue 1: https://github.wdf.sap.corp/sap-cloud-infrastructure/solution-development-issues/issues/505

Checklist

• I have performed a self-review of my code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• I have made corresponding changes to the documentation (if applicable).
• My changes generate no new warnings or errors.

[andypf]

Look good but I'm missing tests. Could you please add some tests?