Default `Image` filtering `Nearest` causes artifacts

[aevyrie]

What you did

Scaled an image in bevy_egui, resulting in aliasing artifacts. See vladbat00/bevy_egui#89

What you expected to happen

I would expect images to default to linear filtering.

What actually happened

Bevy appears to default Images' SamplerDescriptor to Nearest, because it is wgpu's default:

Bevy:

bevy/crates/bevy_render/src/texture/image.rs

Line 134 in 0529f63

sampler_descriptor: wgpu::SamplerDescriptor::default(),

wgpu SamplerDescriptor:

https://github.com/gfx-rs/wgpu/blob/e4553d7e169a6edf1a4f1b2a983b96700fa098f2/wgpu-core/src/resource.rs#L469-L471

wgpu FilterMode:

https://github.com/gfx-rs/wgpu/blob/988990c24d0933c82cdd661708a3f5bcb4533ea3/wgpu-types/src/lib.rs#L3203