Port away from KHTML

Summary:
- Port glossary to QTextBrowser: Straight forward part with just exchanging KHTML functionality with
QTextBrowser, resulting in same results.
- Port detailed information to QTextBrowser: Visual changes are small. This change also puts the general information
into the header to avoid visual inconsistencies between different
pages.
- Remove KHTML Dependency: This patch also makes all implicit KF5 dependencies visible that
were pulled in via KHTML.

Reviewers: #kde_edu, apol, yurchor

Reviewed By: yurchor

Subscribers: yurchor, aacid, kde-edu

Tags: #kde_edu

Maniphest Tasks: T11572

Differential Revision: https://phabricator.kde.org/D23830