NLU intents inputs fail when using special characters

[Naroh091]

When trying to create NLU intents with words that use special characters most of the time Botpress removes those special characters.

To Reproduce

1. Go to the NLU section
2. Create an intent
3. Try to add these phrases (all three basic ways to say 'go back to the menu' or 'menu' in German):

• zurück zu Menü
• zum Menü
• menü

Expected behavior The input works just fine. Instead, the special chars are removed.

Using BotPress 12.30.6

May be related to botpress/v12#1716, but I decided to create a new issue since in this case, the text does not turn red.

[davidvitora]

Not planned, but feel free to submit a PR