[Task] Switch to mjml to handle email templates

[arsforza]

Who requested this feature?

@gulfaraz

User Story

As a developer
I want to use mjml to create email templates
So that emails are easier to create and style

What needs to be done

• Install mjml
• Migrate to object structure
• Test for multiple disasters

After first review with @gulfaraz

• Fix width on mobile
• Set Arial as font
• Add margin between action button and description on mobile
• Fix "from nows from now" typo
• Use correct button labels
• Add Mailchimp footer
• Fix event trigger issued text's size and spacing
• Use date-fns instead of moment
• (optional) Fix rounded buttons on Outlook (Windows)
• Make single-logo countries logos smaller (by limiting height and adjusting width to that?)

[jannisvisser]

@arsforza @gulfaraz

• I have merged the fix.email-logos branch into this one as discussed yesterday.
• I noticed that the single logo countries have a huge logo, but that was already the case before, so decided to not let it block the email logo item, but maybe good to fix in this item still? (made a task above for it)
  

[gulfaraz]

I noticed that the single logo countries have a huge logo, but that was already the case before, so decided to not let it block the email logo item, but maybe good to fix in this item still? (made a task above for it)

You should use height: 50px in the CSS or image height="50" in the IMG tag to set the height of the logo.

[gulfaraz]

The can be closed after merging PRs #1527 and #1594.