Replace propagated channel with non-propagated

Usually when replacing channels IQANdesign will refuse to replace a public channel with a non-public channel.

However, it is allowed to replace a function group output with a non-output channel.

It is also allowed to replace a propagated output with a non-propagated output.

At first it seems to work, the project check gives no errors.

Some time later, maybe the day after when you happen to click on the function group input the reference gets deleted and if it was automatically named also the name.

It would be good if the replace channel function would refuse to work if any of the references will be invalid after replacement.

At least the project check should give a warning afterwards.