Some values are lost when wrapping a custom completer.

Tried wrapping my custom completer in a FuzzyCompleter, and had some problems:

• 'document.getWordBeforeCursor()' is empty, thus not allowing me to debug, as well as flat out rejecting some completions which works unwrapped.
• some yielded Completions inexplicably don't work. I am using the "emojis" library, and in my normal completer, I return this and it works fine

x = self.data['emoji_map'][val]
val_emoji = emojis.encode(x)
yield Completion(text=val_emoji, display_meta=val, start_position=-len(word))

whereas when wrapping it, the completion doesn't show up at all. Although reversing the text and display_meta works, as in:
yield Completion(text=val, display_meta=val_emoji, start_position=-len(word))

I've therefore had to remove fuzzy matching, which is a big sad.

Start by tracing how FuzzyCompleter wraps the custom completer and handles document.getWordBeforeCursor() and yielded Completion objects. Reproduce the issue with the emojis example, comparing wrapped and unwrapped behavior; done means the wrapped completer preserves the lookup word and displays valid completions without reversing text and display_meta.