Fix CUSTOM CSV Export broken with fields including carriage return characters

What
The CUSTOM CSV Export feature is described e.g. on https://doc.nuxeo.com/nxdoc/1010/how-to-export-data-using-document-template-and-automation/
When generating such a CSV with fields including carriage return characters, the resulting CSV is flawed as was described in NXP-30078

How to reproduce
In Studio:

• create a document type Doc with a schema doc including a String-typed field MyString
• configure the JSF or WebUI screen enabling to create/modify/view the fields dc:description and doc:MyString with a textarea input
• create a template > Document template named CSVExport and containing

  Title, Description, Creator, Creation Date, doc:MyString
  <#list This as doc>
  "${doc["dc:title"]}","${doc["dc:description"]}","${doc["dc:creator"]}","${doc["dc:created"]},"${doc["doc:MyString"]}"
  </#list>
  

• create an automation chain MyCSVExport containing

  - Context.FetchDocument
  - Repository.Query:
      language: NXQL
      query: "SELECT * FROM Doc"
  - Render.DocumentFeed:
      template: "template:CSVExport"
      filename: MyCSVExport.csv
      mimetype: text/csv
      type: ftl
  - Seam.DownloadFile
  

• configure a User Action in JSF or a button in WebUI active in Workspace or Folder and calling the previous automation chain MyCSVExport

• Configure a Nuxeo 10.10 with HF up to 10.10-HF45
• deploy the preceding project
• create a Workspace or Folder
• Create a Doc document with a dc:description field looking like

  this is
  a multiline
  description
  

  and a doc:MyString field looking like

  this is
  a multiline
  string field
  

• come back in the workspace or folder and hit the custom buttom performing the custom export CSV and download the CSV file
• edit the CSV file with a text editor and notice in the CSV file the newlines are included in the fields

Caveats

• reproduced as is, the CSV file is not broken as a CSV file: the carriage returns are included in fields with double quotes, this is common practice but not a standard
• when you open the file in Excel, although there is only one title line and 1 document, the Excel displays more than 2 active lines => Sorting per columns is then impossible as giving meaningless result
• SInce NXP-30078, the expectations are that multiline comments should appear as 1 single line => This is not the case here

Discussion

• If it is decided NOT to fix this ticket, should one advise to use the custom CSV Export feature as a workaround for fields including multiline values?