Closes#9946
# Objective
Add a new type mirroring `wgpu::SamplerDescriptor` for
`ImageLoaderSettings` to control how a loaded image should be sampled.
Fix issues with texture sampler descriptors not being set when loading
gltf texture from URI.
## Solution
Add a new `ImageSamplerDescriptor` and its affiliated types that mirrors
`wgpu::SamplerDescriptor`, use it in the image loader settings.
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## Changelog
### Added
- Added new types `ImageSamplerDescriptor`, `ImageAddressMode`,
`ImageFilterMode`, `ImageCompareFunction` and `ImageSamplerBorderColor`
that mirrors the corresponding wgpu types.
- `ImageLoaderSettings` now carries an `ImageSamplerDescriptor` field
that will be used to determine how the loaded image is sampled, and will
be serialized as part of the image assets `.meta` files.
### Changed
- `Image::from_buffer` now takes the sampler descriptor to use as an
additional parameter.
### Fixed
- Sampler descriptors are set for gltf textures loaded from URI.
756fb069b1