Removed Jed from the headless build and instead let `__` call sprintf.
It's now up to downstream users for `@converse/headless` to decide
whether they want i18n support for the few translatable strings in that package
and to implement it themselves.
- Declaratively render the emoji picker dropup
- Got rid of converse-emoji-views
- Adapt OMEMO to the new buttons stuff
- Make emojis json global, to try and speed up tests
- omemo: Move functions to the top of the module