RT490: Add supported charset - Fixes #11020 - Fixes #11309

[pbarrette]

Added additional characters supported by the RT-490 display.

[kk7ds]

Looks good, I'll merge this in the next couple days for the next build.

Note for the future, you can just do this in-place and git push -f to update the PR so you don't have to create a new one.

Thanks!

[pbarrette]

Thanks for the help.

I'm using Github Desktop at the moment. It doesn't always sync the way you'd expect and I didn't trust a force push, so it was just easier and cleaner to rebase.