CherryPick LocaleMatcher API in ICU

Merge
https://github.com/unicode-org/icu/pull/714
https://github.com/unicode-org/icu/pull/671
https://github.com/unicode-org/icu/pull/747

Bug: v8:7051
Change-Id: I3aa88f0b08d3fcfe89f07f71bfd5db0a6c337790
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/deps/icu/+/1763047
Reviewed-by: Jungshik Shin <jshin@chromium.org>
37 files changed