Update Emojibase and switch to IamCal (Slack-style) shortcodes

for consistency with shortcodes commonly used by other platforms, as
was decided in https://github.com/vector-im/element-web/issues/13857.

One thing to be aware of is that the currently used version of Twemoji
does not support a few of the newer emoji present in Emojibase, so these
look a little out of place in the emoji picker. Optimally Twemoji would
be updated at the same time, though I don't know how to do that.

Signed-off-by: Robin Townsend <robin@robin.town>

package.json

@@ -64,8 +64,8 @@
     "counterpart": "^0.18.6",
     "diff-dom": "^4.2.2",
     "diff-match-patch": "^1.0.5",
-    "emojibase-data": "^5.1.1",
-    "emojibase-regex": "^4.1.1",
+    "emojibase-data": "^6.2.0",
+    "emojibase-regex": "^5.1.3",
     "escape-html": "^1.0.3",
     "file-saver": "^2.0.5",
     "filesize": "6.1.0",