maybe add an optional note field to transaction so the receiver knows who sent the
btc
This has been discussed many times. But in any case: If you encounter this as a problem it means you are re-using addresses, which is discouraged for good reasons.
Otherwise, when someone wants to send you BTC they need to request a new receiving address from you. Along with this request they can also send a message, over whatever channel is used to negotiate the payment.
If you're just posting a static bitcoin address somewhere for donations, consider it an anonymous (wel, pseudonymous) gift jar.