Replace WhisperBack.mail_appended_info with a dictionary

Currently we set WhisperBack.mail_appended_info to a big string containg all debugging inforamtion. We should replace this by a dictionnary of {filename:content, filename:content, ...} so that we can attach each in a separate MIME attachement.

Feature Branch: feature/8514-7180-whisperback-remove-right-pane-and-refactor,saschamarkus/whisperback:feature/8514-Replace-mail_appended_info-with-a-dictionary

Attachments

• 0001-feature-8514-Replace-WhisperBack.mail_appended_info-.patch
• 0002-feature-8514-Replace-WhisperBack.mail_appended_info-.patch
• debug.json

Parent Task: #6183

Related issues

• Related to #15793
• Blocks #8722
• Blocked by #15472 (closed)
• Blocks #13241 (closed)

Original created by @alant on 8514 (Redmine)