Add unread icons.

[pixlwave]

Adds Unread and Read icons.

Discussed with @amshakal about whether we should rename these to something more descriptive in case we have more things that need read/unread iconography in the future, so if that happens the icons would need renaming, otherwise this is ready for review. Please feel free to merge after reviewing 🙂

[jmartinesp]

The icons look fine on Android and the generated code makes sense.

However, at a personal level I think the icons are a bit weird since they're meant for email . In some other apps I've seen something like this used instead:

Although arguably this can also be misleading because we don't have the concepts of 'checks' in the app.

Anyway, I'm approving this since it's not a big deal.

[amshakal]

I have changes the names in the compound file.

As far as the email analogy is concerned, yeah it's true, it's taken from an email context, but at least we would be using standard known icons to represent the features. An alternative could be to use a message bubble with a dot and without a dot. But usability wise, it shouldn't matter.

[pixlwave]

Alright, updated with the rename 👍