Fix tables showing incorrect amount of pages, and some other table issues

[juhanikat]

Fixes #817. Also fixes:

• Occurences table navigating back to first page as soon as user tries to go to another page
• console error related to the menu bar of the Occurences table
• rerender loop in TableView caused by a dependency inside a useEffect.

[Copilot]

Pull request overview

This PR addresses several pagination/state issues in the shared TableView used across the frontend, primarily fixing incorrect page counts (Issue #817) and stabilizing server-side pagination behavior for the occurrences/cross-search table.

Changes:

• Adjusts TableView pagination behavior by only providing rowCount for server-side pagination and disabling automatic page-index resets when server-side pagination is enabled.
• Introduces rowCount state updates based on server-side results (full_count) and resets pagination when filters/sorting change.
• Updates CrossSearch export menu rendering to avoid a React fragment inside an MUI Menu.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
frontend/src/components/TableView/TableView.tsx	Reworks pagination + row counting logic to fix incorrect page counts and server-side paging resets.
frontend/src/components/CrossSearch/CrossSearchTable.tsx	Changes the extra export menu items wrapper used inside the table export menu.

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