*IMPROVED* Long filename samples won't load

[RMBLRX]

I just noticed this issue in 1.18C, but it took a bit to realize sample name length was causing the error. I don't mind the restriction so much, but it was confusing at first because we get an unspecified error when attempting to load such samples. A more descriptive error message would be helpful for new users, though I do imagine it would be just as easy to lift the character cap.