This patch imports the full list from unicode.org instead of
special-casing a few characters as was done previously.

With this patch, '👍️' (1F44D FE0F) should look the same as '👍' (1F44D).
Without it, it will look like '👍‌️'.

As a simple regression test, '✔' (2714) should still as "text" while '✔️'
(2714 FE0F) should still display as an emoji.

Fixes https://github.com/alphapapa/ement.el/issues/137

NOTE: I'm not a Unicode expert, nor do I understand how Emacs handles
Unicode (beyond what was required to implement this patch). But this
patch appears to work and I can't find any regressions.