KIO::UDSEntry, switch to a single std::vector for more performance.
This new implementation is the fastest in the [[ https://phabricator.kde.org/D12659 | autotests ]].
This new implementation has asserts in the insert() methods to detect an already inserted entry, in that case the insert() call must be changed to a replace() call.
Detected so far:
* KFileItem::init(), setTime(), setLocalPath() because m_entry can have entries from the constructor.
* KFileItem::setName, when renaming a file in dolphin.
* ListJobPrivate::slotListEntries, running Kfind.