Implemented the VKSamplers based on the documentation in GPU_texture.hh.
They used to be reversed engineered from the OpenGL backend, however
Vulkan has better control over mipmap filtering and OpenGL needed to
combine some flexibility inside the min/mag filtering.
Changes:
- Mipmap filtering was always on, not only when `GPU_SAMPLER_FILTERING_MIPMAP`
is used.
- Mipmap filter mode is always set to linear. This is not according to the
documentation, but matches OpenGL and the render tests.
Fixes#136439, #138111
Partial fix#137436 - seam isn't there, inf can still be part of the
texture.
Pull Request: https://projects.blender.org/blender/blender/pulls/138313
098990b172