Set wrapMode to Text.WrapAnywhere.

Summary:
Means long main texts don't get truncated. One of the main uses
for tooltips is to show full text for things that are truncated
in the usual UI, so this is a bad default.

BUG:375141

Reviewers: Plasma, mart

Subscribers: plasma-devel, Frameworks

Tags: Plasma, Frameworks

Differential Revision: https://phabricator.kde.org/D4189