Few new strings added during soft string freeze in Krita

Hi,

last week on January 20th a commit I authored got merged into Krita. The
commit is here:
https://invent.kde.org/graphics/krita/-/commit/4d51b11f394bfd00df1b65197179147ad36301dc

That was during a soft string freeze, and just before the hard freeze start
date (which happened one day later on January 21st).

This commit adds three new strings that are error messages. They are
somewhat important because otherwise the user would have no indication for
why the tool doesn't work (it doesn't even react in any way, leaving users
stumped and confused) in a relatively common scenario, and the tool is also
commonly used.

I intended to send a message about it immediately but unfortunately forgot,
I'm sorry. I hope it doesn't cause too much disruption in your work.


Best regards,
tiar