Add support for common sidechain channel naming

[johnmannix]

When you build a plugin with 4 channels - 2 for stereo input and 2 for side chain - the current naming does not reflect that for users of the plug-in. You get Input 1 - L & R and Input 3 - L & R. It would be nice to support Input L & R and Sidechain L & R, which is common in other plug-ins.

[aaronventure]

This would actually be great for multichannel plugins. General channel naming for inputs and outputs.

[ThomAce]

+1: Would be great to have a component, snippet, whatever to read all the available tracks from the actual DAW and can be populated as a list / dropdown menu, etc and could be configured from the plugin itself. At the moment I did not found any workaround for this.