Now that `emoji_collection` and `emojis_by_name` are global
datasources in the webapp we need to rename things carefully
to reflect their actual meaning. The fact that emoji code is
used as a css class for unicode emoji is one thing but it is
not its sole use so renaming it seems a good idea.
We were using underscore as a delimiter in `emoji_id` in emoji picker
but since `emoji_type` also contains underscores, it seems wrong to
use underscore as a delimiter. This commit switches `emoji_id` to use
comma as a delimiter instead of underscore.
Now that we display the name and aliases of the currently focused
emoji at the bottom of the emoji picker, we don't need to display
the title text for emojis separately.
Fixes: #6111.
Harshit Bansal
Tim Abbott