Stroke alignment on «Solidify Stroke»

The «Solidify Stroke» assumes that all strokes are `StrokeAlign::Center` [sic] causing it to give the incorrect results for `StrokeAlign::Inside` and `StrokeAlign::Outside`.

The alignment can be set in the properties of the stroke node:

A proper implementation of the algorithm must deal with intersecting bézier paths in the same way as the SVG and vello renderer. An interesting case can be seen here where we have a closed path made of just two intersecting cubic béziers:

If the path is not fully closed, then the centre alignment must be used to match the renderer. Also note that a path can contain multiple contours. These can likely be dealt with individually?

To deal with intersections of paths in an efficient the [`linesweeper` crate](https://docs.rs/linesweeper) can be used since it is already included as a dependency.

The `kurbo::stroke` function only supports centre alignment. I'm not sure if it is within scope to add other alignments to it.

As reported by [@Menxs on discord](https://discord.com/channels/731730685944922173/1134981447539761273/1544038003955990538).

Comienza localizando la implementación de Solidify Stroke y su gestión de StrokeAlign. Compara su comportamiento para rutas abiertas, cerradas, que se intersectan y con múltiples contornos con el renderizador SVG y vello, y revisa la dependencia disponible linesweeper junto con kurbo::stroke. Se considera terminado cuando las alineaciones Inside, Outside y Center producen resultados coincidentes y las rutas abiertas conservan la alineación Center.

Escrito por el modelo de indexación a partir del texto del issue.