Rename MLBuffer => MLTensor

[bbernhar]

The recent revision of the proposed MLBuffer spec no longer represents a low-level concept of device memory storage, as these buffers are now tied to specific shapes and data types. Converting between MLBuffer(s) of different sizes will likely require copying (vs reinterpret_cast). To avoid confusion with other 'buffer-as-bytes' types (e.g., GPUBuffer, ArrayBuffer), I propose renaming MLBuffer to MLTensor.

👍 = I vote yes to rename

[a-sully]

SGTM. I've been drafting an explainer for MLBuffer and the first sentence is:

This explainer proposes an MLBuffer interface which represents a tensor...

I'll find-and-replace and put up the MLTensor explainer shortly :D

[a-sully]

MLBuffer never made it into the spec, so the only artifacts saying "MLBuffer" are issues and PRs (and lots of Chromium code which @bbernhar has been diligently refactoring). We could retitle issues including MLBuffer. The explainer PR already uses MLTensor. Otherwise... I think we can close this? :)

[bbernhar]

I think we can close this? :)

SGTM.