Fix WebGPUTextures

[LeviPesin]

Related issue: -

Description

Without this fix small DataTextures render white in WebGPU. Example: https://jsfiddle.net/3jb9eka0/ (compare to WebGL version: https://jsfiddle.net/3jb9eka0/1/) -- the texture should render green but renders white. With this PR it renders red (see https://jsfiddle.net/3jb9eka0/2/) due to another bug -- I will file an issue for it after this PR will be merged.

They produce the following error:

Required size for texture data layout (264) exceeds the linear data size (16) with offset (0).
    at ValidateLinearTextureData (..\..\third_party\dawn\src\dawn\native\CommandValidation.cpp:257)
    at ValidateWriteTexture (..\..\third_party\dawn\src\dawn\native\Queue.cpp:517)
    at WriteTextureInternal (..\..\third_party\dawn\src\dawn\native\Queue.cpp:323)

I think it occurs due to miscalculation of bytesPerRow (and therefore required buffer size, see https://gpuweb.github.io/gpuweb/#abstract-opdef-validating-linear-texture-data). Not sure why this formula was used instead of more simpler and (I think) more correct one? (It was introduced in 317bd1c with the support for DataTextures in WebGPU.)

/ping @sunag @Mugen87