Update Brand Kit

Color role assignment to write. Unknown keys are rejected.

Logo role assignment to write. Unknown keys are rejected.

Typographic role assignment to write. Unknown keys are rejected.

A single brand kit with its colors, logos and fonts.

A brand kit imported from a website is assembled in the background. While status is loading the collections and role fields are provisional and may be empty or incomplete; the import has finished contributing to them once status is completed. A kit whose import failed reports error and keeps whatever was assembled before the failure. A kit can still be edited in the HeyGen web app afterwards, so completed means the import is done, not that the kit is frozen.