Show full name in tooltip if shortened

Created by: Famlam

If you have two names which are identical in the first 20 characters, you will not be able to distinguish (for example) the following two names in Multiplot mode: H1_600_specialsample_beforeheating H1_600_specialsample_afterheating

This PR adds the full name as a tooltip of the shortened name, so that by hovering your mouse you can still observe which spectrum corresponds to which name