Fix compatibility of CSV export with fields including carriage return characters

When a document has a field which includes a carriage return character (e.g. dc:description can have a multi-line description), then the export CSV file is invalid.
Namely, some lines are truncated and their truncated part is elsewhere in the file but not at the following line

E.g.
Expected format:
[...]"my multi-
line comment
is a valid one"[...]
which includes the field within double quotes as a common convention: https://stackoverflow.com/questions/566052/can-you-encode-cr-lf-in-into-csv-files

Actual generated forrmat of the CSV file
[...]"my multi-[...]
[...]
is a valid one"[...]
line comment[...]

Consequence: Excel cannot import successfullly the CSV export file