Refactor CClientDlgOnConnectDisconnectBut() #3401
Description
This should be implemented by switching the `connect` setting for the signal handler for the button, rather than having one signal handler with an if that consults the state of the client.
Button life-cycle:
- (public) ConnectDlg onClickConnect is connected to (private) ClientDlg onConnectDlgConnect
- onClickConnect launches ConnectDlg if it's not already open (and nothing else)
- onConnectDlgConnect disables the button and asks the client to connect to the provided address
- onConnect switches the onClick handler to onClickDisconnect and enables the button
- onConnectFailed just enables the button (keeping the onClickConnect handler) -- although, if Client is passing an error, here's where it would get displayed to the user
- onClickDisconnect disables the button and asks the client to disconnect
- onDisconnect (which should be handled) switches the onClick handler to onClickDisconnect and enables the button
Originally posted by @pljones in #3372 (comment)