Indicator when input is captured

## Feature Request
Please have a visual indicator that the input (keyboard & mouse) is captured. This could be for example an additional border on the icon in the status menu icon.

## Use Case
Most of the time I work in the VM created by UTM. To avoid shortcut conflicts I usually make the VM capture the input. However, there are some situations where I make use of the host system. Due to the fact that the input is quite seamless I don't notice after a while, that the input is not completely captured, only when using named conflicting keyboard shortcuts. A visual indicator would help me to do a brief double check if my settings are the way I would expect them.