Show sources of plugin sidechain inputs

[Jürgen B]

There is no visual indication if a plugin has sidechain inputs and whether something is routed to them. It would be very helpful to see which sources are sent to the secondary inputs of a plugin. So far, it's only possible to check routing from source to target by looking at the sends of all tracks and busses. Such a feature would make it much easier to verify that the plugin is set up correctly and gets the desired input from the desired sources.

In the GUI, this could be placed somewhere in the common header section of a plugin window (where bypass, preset, learn, SRW, pin, ... are located).

Even better would be the possibility to establish a new send from the target plugin, i.e., to select the track which should send to the sidechain input of the plugin.