'set_frame_style' is what Frame itself uses to set the value, and a
significant number of GML files use 'frame_style' instead of just
'style', so let's switch to it and use it everywhere consistently.
Previously the GML compiler did not support object properties such as
`content_widget: @GUI::Widget{}` for GUI::ScrollableContainerWidget;
this commit adds support for such properties by simply calling
`set_<key>(<TProperty>&)` on the object.
This commit also removes the previous hack where
ScrollableContainerWidget was special-cased to have its singular child
used as the content widget; the only GML file using this behaviour was
also changed to be in line with 'proper' GML as handled by the GML
Playground.
Previously, Frames could set both these properties along with a
thickness to confusing effect: Most shapes of the same shadowing only
differentiated at a thickness >= 2, and some not at all. This led
to a lot of creative but ultimately superfluous choices in the code.
Instead let's streamline our options, automate thickness, and get
the right look without so much guesswork.
Plain shadowing has been consolidated into a single Plain style,
and 0 thickness can be had by setting style to NoFrame.
This will allow easily adding components such as a search box. Also,
increase the number of emoji per row. This does not fix the issue where
too many emoji will cause the dialog to grow limitlessly, but it looks a
bit more reasonable now with the number of emoji that we have.
