Profile images seem to be loading significantly faster after
moving file fetching logic to the native code and removing the
artificial delay.
TDLibFile is a generic object which can hopefully be used
elsewhere as an efficient replacement for JavaScript.
https://doc.qt.io/archives/qt-5.6/qtquick-performance.html
In general, "property var" should be considered to be superior to "property variant" for every use-case from QtQuick 2.0 and newer (note that "property variant" is marked as obsolete), as it allows a true JavaScript reference to be stored (which can reduce the number of conversions required in certain expressions).
