- Implement support for mipmapping:
  Involved fixing retrieving correct texel pointers for each mip level.
- Implement addressing mode.
- Implement filter mode.
- Removed textureSize(). We already have an implementation of
  OpImageQuerySize which doesn't require the sampling code.

For now, these parameters are converted to the legacy sampler enum
values to avoid a big refactoring which may break functionality before
we pass the tests. Future changes will eliminate them in favor of using
the Vulkan sampler parameters directly.

Bug: b/129523279
Test: dEQP-VK.texture.filtering.2d.formats.r8g8b8a8_unorm.*
Test: dEQP-VK.pipeline.sampler.view_type.2d.format.r8g8b8a8_unorm.*
Change-Id: I313e598ae61c0016a5a929bf5c1a53b66b3ff0d1
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/29770Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>