Feature / Add parser for emails

What does this MR do and why?

This PR is continuation for this issue.

Screenshots or screen recordings

In this issue you can look on screenshots how it was looking

Now:

Example of rendered collapsible block which was rendered from email with HTML type:

How to set up and validate locally

1. Download MIRO email example: miro_board.eml
2. Update email with your projects email in Service Desk. This one eyero-ext+flightjs-flight-7-issue-@gitlab.com
3. Start local env: gdk start
4. Run bin/mail_room start
5. Run spring rails c in gitlab directory.

Then in console:

raw = File.open("miro_board.eml").read
::ServiceDeskEmailReceiverWorker.new.perform(raw)

Go to the project issues and open newly created issue.

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.