[Solid] Port QRegExp to QRegularExpression

Summary: Port QRegExp::exactMatch() with QRegularExpression::anchoredPattern().

Test Plan: make && ctest

Reviewers: Frameworks, dfaure, meven, apol

Reviewed By: meven

Subscribers: kde-frameworks-devel

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D26470