Moves VSNPrintf, SNPrintf and StrNCpy out of utils/utils.h into
base/strings.h.

Bug: v8:11879
Change-Id: I0e165cb27c42f89c9acd1c6378514b40a90cd18d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2972732
Auto-Submit: Dan Elphick <delphick@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75308}