Add overload for `addFont` to directly add `Uint8Array` encoded font

[septatrix]

Currently addFont receives its payload as a base64 encoded string and converts it to a Uint8Array. However, oftentimes the font is first loaded with fetch which already provides the data as Uint8Array. Currently one has to do some annoying dance just convert it to base64 which could be completely avoided (and remove some unnecessary computation) if it directly offered to consume the Uint8Array encoded data