Upgrade to Unicode 16.0 and add support for almost all gemoji aliases

[shane-tw]

This upgrades to Unicode 16.0, using this Unicode 16.0 gemoji PR as a base.

There wasn't much documentation explaining how emojis.json was originally generated for this repo, so I wrote a Python script to merge vdurmont/emoji-java's emojis.json file with github/gemoji's emoji.json, preserving any of this repo's aliases.

Anyway, any aliases e.g. :like:, etc. which were a thing for this repo remain a thing after this PR.
It's mostly backward compatible, main notable differences (matching github/gemoji behaviour):

• Many emojis had FE0F added to them (just makes the emoji render as a picture, safe).
• :jar: now maps to 🫙 , not 🏺 (:amphora:).
• :beetle: now maps to 🪲 , not 🐞 (:lady_beetle:).
• :satellite: now maps to 📡 , not 🛰️ (:artificial_satellite:).

To maintain backwards compatibility, the below differ from gemoji:

• :ng maps to 🇳🇬 , not 🆖 (:squared_ng:).
• :om: maps to 🇴🇲 , not 🕉️ (:om_symbol:).

If you want a diff, I recommend reviewing individual commits, as the sort commit otherwise makes it hard to review.

EDIT: I added a hack to strip FE0F on all inputs prior to converting from emojis to aliases, as otherwise this repo would no longer map some emojis if people entered them without the FE0F. Commit here. I'll revert that if wanted.