This also undeprecates Message::GetStartColumn API.

The simple versions are easier to use for the embedders and have the
same implementation as the complex versions.

Bug: v8:7560
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I656161b04c5d9de6d1de9435b7825009f96572a5
Reviewed-on: https://chromium-review.googlesource.com/963322
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51951}