Since commit 6fefe75a1c the handling
of forward-focus bindings happens before the resolve_expressions pass,
which means that we cannot rely on type mismatch
error handling yet.
Fixes#4475
Achieve this by generating a `focus()` function for such components
and call it from the outside.
This replaces the previous focus handling with what should be cleaner:
- Any `forward-focus: some-element;` is basically syntactic sugar for
`public function focus() { some-element.focus(); }`.
- The init code gets simplified to calling focus() on the root, if it's
available.
Since the `focus()` functions are now generated in the imports pass,
they become visible in the style checker. That means the checker
requires consistent focus handling between the styles.
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.
