Add Emoji properties

Cherry pick  http://bugs.icu-project.org/trac/changeset/38183
to add the support for Emoji properties.

This will be followed by a Blink change to use the API.
( https://codereview.chromium.org/1856353002 )

There's no need to rebuild ICU data because Unicode character
properties are hard-coded in the C++ source files that are
patched by the cherry-pick above.

source/data/in/{pnames,uprops}.icu are updated just for the
record, but they're not actually used. The same is true
of files in source/data/unidata.

BUG=583378
TEST=None
TBR=drott

Review URL: https://codereview.chromium.org/1864463002 .