Summary:
- updating a web page using `QtWebEnginePage::load()`
  in `StandardDocumentationView`does not seem to work for the
  Qt documentation pages and only using a new widget does the job
- adding a url to the documentation history when showing a page now
  is the default, which reverts 3f7a93af
- requires similar changes in kdev-php

BUG 393445

Test Plan:
- navigate in Qt documentation between different classes (QString->QChar for example)
- navigate in manpages
- navigate in PHP documentation (with changes applied to kdev-php)

Reviewers: apol

Reviewed By: apol

Subscribers: apol, kdevelop-devel

Tags: #kdevelop

Differential Revision: https://phabricator.kde.org/D12793