Add function to get interop ID from user-facing name

For apps that write file formats that take a color space string, the best practice is to write the Interop ID. Therefore, it would be helpful to have an API call to take the user-facing name (i.e., the canonical name) and return the Interop ID.

If the color space has the Interop ID attribute, this is straight-forward, but the fallback should be to search the color space's aliases to see if a known Interop ID is present (in particular, the Color Interop Forum IDs).