This commit finally has a working basic slide_obj implemented in Rust!
There are likely still some things that need to be tweaked and
massaged in order for things to translate back and forth from QML to
Rust.
The key was to make the old SlideObject written in C++ to act as a
bridge between QML and Rust. QML can't seem to understand CXX-QT's
QMap_QString_QVariant type as a QVariantMap and thus didn't translate
the Javascript object properly. Having the call first go into a C++
class translated it and then was trivial to pass into Rust.
This object is still unfinished, but it will later serve as our main
object to connect to for the slides that are shown on screen. All of
this needed some heavy tweaking and I still need to learn more about
rust, but the beginnings are there and it will be worth it to have the
safety and speed that rust provides
