Do the default_geometry pass before injecting elements:
The reason is that the defaut_geometry pass must know if an element is in
a layout and what kind of default geometry needs to be applied depending
on its actual structure, not whatever results after we injected elements
We were relying on the default_geometry pass to set the size of elements,
but that doesn't work for elements that are not covering 100% of their
parents by default. So to that manually instead.
Fixes#915
Move "internal" crates into the `internal` directory. This first batch
includes most of sixtyfps_runtime but leaves the rendering backends
alone for now.
pre-commit applied some cleanups to the moved files:
- Consistent newline at end of file policy
- trimming trailing whitespace
- Formatting Cargo.toml files.
