rich text signed messages - send out with cid instead of img tags?

[tomholub]

    if (choices.richtext && !choices.encrypt && !choices.sign && msg.body['text/html']) {
      // extract inline images of plain rich-text messages (#3256)
      // todo - also apply to rich text signed-only messages
      const { htmlWithCidImages, imgAttachments } = this.extractInlineImagesToAttachments(msg.body['text/html']);
      msg.body['text/html'] = htmlWithCidImages;
      msg.attachments.push(...imgAttachments);
    }

to be sure, not sure what the right approach is - needs to be tested for compatibility. For now putting it into "later" milestone.

Originally posted by @tomholub in #3256 (comment)