Describe the bug

We have been largely exploiting yarpmanager to run demos involving several applications running on different PCs using different OS. So far, everything is great. Some difficulty arises when yarpserver is placed in a very delayed network. In this case, clicking the wrong button might render the system unusable. To give an example, if we press the refresh all button, it is not possible to do anything else in the application until all the applications, connections, and resources have been checked. The problem is that in case of a delayed network, this operation might require minutes. The problem gets worst if you try to close the application that got stuck as the entire yarpmanager gets completely stuck

To Reproduce
One possible way to reproduce it is to set yarp conf to an IP not reachable, and then open yarpmanager without running yarpserver. Then, open the application with the largest number of applications and press on the refresh all button. Then, try to close the blocked application

Expected behavior
When attempting to run another action while another one is running, yarpmanager should simply stop the previous one. At the same time, if the user wants to close the open application, it should close without blocking the entire yarpmanager.

Screenshots
In the following I just tried to open an application and then I try to close it immediately after. In this specific case, the issue is that yarpserver is not running, but the same happens when yarpserver is in a delayed network

Configuration (please complete the following information):

• OS: Ubuntu/Windows
• yarp version: 3.9.0
• compiler:

Additional context
Add any other context about the problem here.

cc @randaz81 @traversaro @Nicogene @GiulioRomualdi