ocioview: MatrixTransform input parameter persistence

When editing a MatrixTransform in ocioview, you have the option of using a number of matrix constructors (fit, sat, scale, view). These take simplified input parameters and populate the transform's matrix and offset arrays. The problem is that there is currently no persistence for the chosen input method. The constructors work for initial entry, but reloading the transform from the config loses the input parameters.

MatrixTransform supports storage of FormatMetadata, which is primarily used when transforms are created from reading a CLF/CTF file. An element could be added to the transform's metadata to store ocioview data including Matrix parameters. This would also allow use of new transform constructors, such as using colour-science data to easily populate matrices with color primary or chromatic adaptation transforms.

Comienza rastreando la edición de MatrixTransform y la recarga de la configuración en ocioview; después, inspecciona cómo MatrixTransform almacena FormatMetadata. Define la representación de los metadatos para el constructor seleccionado y sus parámetros, y confirma que guardar y volver a cargar conserva las entradas del constructor sin afectar a los metadatos CLF/CTF existentes.