[tone] New 'Neutral' or 'Casual' Tone for AI compose

Opinionated feedback so it might not be worth much, but I'd like a 4th tone option that'd be best described as 'casual' or 'neutral'.

I find our current options (professional, friendly and empathetic) to sometimes be 'too much' in the way they phrase things; a more minimalistic option that would more or less just state facts in a courteous way would make a good addition IMO.

• Our professional tone does precisely what it's meant to, but it is only appropriate with a handful of customers.

• Friendly can sometimes be too casual or simply too much in the way it phrases things

• Empathetic is similar to professional; I only need it for specific cases.

I realise this might be done through our 'Make more concise' feature, but I thought it could be interesting to save our users a click (and they might not think of that option themselves)