CSV export does not contain descriptions

[rospe]

Describe the bug
When downloading a CSV in the search results page, the results.csv does not contain table descriptions.
The header is part of that CSV, but the contents of the rows is not the table documentation but the title of the table.

Besides, the download does not work when we select too many tables (150 in this case), the download can only be generated in subsets of 10, otherwise it fails (see Screenshots). "Thread limit exceeded replacing blocked worker" is the error in GMS in that case.

To Reproduce
Steps to reproduce the behavior:

1. Go to

2. Click on 'Download'
3. Open results.csv and compare description column

Expected behavior
Export contains table documentation.

Screenshots

Additional context
Same behaviour in Datahub 14.1 and 15.0.1