Extern: Entries in table export depend on current viewport and state of ext_references

extern: https://gitlab.com/linkahead/linkahead-webui/-/issues/162

This table after exporting:

| ID   | date       | project |
|------|------------|---------|
| 9720 | 2020-11-11 | 2020_l  |
| 9722 | 2020-11-24 | 2020_l  |
| (...)|    (...)   |  (...)  |
| 9725 | 2021-01-12 | 2155    |
| 9727 | 2021-01-19 | 2155    |

• Fixed
• Followup issues created if necessary