[FilesTS] Add chrome.wallpaper definitions

The file_manager_commands file uses the chrome.wallpaper APIs to set the
users wallpaper. Introduce a new TS definition file at
//tools/typescript/definitions and update the caller site to use the
new auto-generated promise type instead of callbacks.

Bug: b/289003444
Change-Id: I4aa2f7c1360a4e766455cf9f7c7cdfb91d964e11
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5108721
Commit-Queue: Ben Reich <benreich@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1236009}