Redo the handling of Emoji data

Redo the handling of Emoji data

Use the data files from https://github.com/milesj/emojibase.git
as source for our Emoji data. Slightly change our data format by
adding a group to each item, in both the Emoji data and in the
setting for recent-emoji.

Install translated versions of the data as separate resource
bundles in $prefix/gtk-4.0/emoji, and load them when appropriate.

Currently, we have data for de, en, es, fr, zh, with data taken
from Unicode 13 and CLDR 13.

Fixes: #950 #1511