Add notes summary into csv export for vulnerabilities

What does this MR do and why?

Add notes summary into csv export for vulnerabilities.

Related issue: #341149 (closed)

Example of CSV file: root-oct-7-2022_vulnerabilities_2022-11-04T1120.csv

How to set up and validate locally

1. Create a project with the following gitlab-ci.yml

include:
  - template: Security/Container-Scanning.gitlab-ci.yml
variables:
  DOCKER_IMAGE: python:3.4-alpine

1. Make sure the pipeline has been run for the default branch
2. Go to Security & Compliance -> Vulnerability Report
3. Change the status or add a note to one of the existing vulnerabilities
4. Click on Export button in order to generate a csv formatted list of vulnerabilities
5. Compare the new column Comments from the csv file against the notes from the vulnerability details

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.