Custom binder for MARISS

* Add custom actions on WFS Grid
 * Generalize the `actioncolumn` adition on this plugin
 * Allow more than one button in the generated column
* Extract part logic present binding various widgets to a custom widget
 * Expand panel that contains the download list
 * Bind download list with WFS grid with custom actions
 * Bind WFS grid with the playback widget and the current extent
Ussage of custom binder

* Add custom actions to WFS grid
* Use the custom binder for the project