Add autotests for <SELECT "a" + "b"> and <SELECT "a" || "b">
See https://phabricator.kde.org/T677
Grammar is checked already but result of the concatenation needs to be tested too. This is beyond of the parser test at the moment.
See https://phabricator.kde.org/T677
Grammar is checked already but result of the concatenation needs to be tested too. This is beyond of the parser test at the moment.