Allow using send button when there is no message text

[singpolyma]

In my app sometimes a user can attach a file, then push send, without typing a message. I can use sendDisabled to make the button become enabled when there is an attachment, but clicking it does not trigger the onSend handler because of https://github.com/chatscope/chat-ui-kit-react/blob/master/src/components/MessageInput/MessageInput.jsx#L134

I think this check should be replaced with a sendDisabled check, or no check since the button disablement should be enough to prevent this from being called when we don't want it.

[PavelKudrautsau]

This is just as interesting to me, hint how to implement it

[PavelKudrautsau]

@singpolyma please you can help with it?

[supersnager]

I think this behavior should be controlled by dedicated flag.
For now as a workaround you can set <MessageInput sendButton={false} />, and use custom send button like in this story:
Wrapped MessageInput

Related issue: #7