* Allow setting the scale filter for `glow` backend
This commit adds a `set_scale_filter` method to the `glow` painter so that
textures can be set to scale using nearest-neighbour scaling rather than
linear. This is useful for pixel art.
I wasn't entirely sure what kind of API you want for this kind of change so I
went with what seemed least intrusive, I don't mind doing something more
holistic if this isn't what you had in mind.
* Rename scale_filter -> texture_filter
* Store the TextureFilter directly
* PR link in changelog
* Use inter-doc links
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
