[WIP] Add option to always show images of all messages

Still need to implement a condition which will not show the images of
messages in spam / junk folder.
4 jobs for show-all-images in 16 minutes and 12 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #102447
deb-package

00:03:31

passed #102445
fedora

00:03:18

passed #102448
flatpack-package

00:06:30

passed #102446
ubuntu

00:02:52