Rename async local storage to KV storage

Follows https://github.com/WICG/kv-storage/commit/7057d3dc66101fa237bbc6cd01ad4633b520f65b.

This also removes .tentative from the web platform test filenames, as there exists a spec these days.

Binary-Size: needed to implement the feature. Enabling gzip is tracked in crbug.com/920264.
Change-Id: Ie34291da9cf0a25e6a70f2a97f27459ee6b58f13
Reviewed-on: https://chromium-review.googlesource.com/c/1407433
Commit-Queue: Domenic Denicola <domenic@chromium.org>
Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623344}
18 files changed