Allow video sources to be added to Shuffleboard (#1453)

Add a Sendable wrapper for VideoSource objects.

Add convenience methods for adding video sources directly to containers
so users won't have to manually wrap video sources.

wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardContainer.h

@@ -24,6 +24,10 @@
 #include "frc/shuffleboard/ShuffleboardComponentBase.h"
 #include "frc/shuffleboard/ShuffleboardValue.h"
 
+namespace cs {
+class VideoSource;
+}  // namespace cs
+
 namespace frc {
 
 class ComplexWidget;
@@ -104,6 +108,17 @@ class ShuffleboardContainer : public virtual ShuffleboardValue,
    */
   ComplexWidget& Add(const wpi::Twine& title, Sendable& sendable);
 
+  /**
+   * Adds a widget to this container to display the given video stream.
+   *
+   * @param title    the title of the widget
+   * @param video    the video stream to display
+   * @return a widget to display the sendable data
+   * @throws IllegalArgumentException if a widget already exists in this
+   * container with the given title
+   */
+  ComplexWidget& Add(const wpi::Twine& title, const cs::VideoSource& video);
+
   /**
    * Adds a widget to this container to display the given sendable.
    *
@@ -115,6 +130,16 @@ class ShuffleboardContainer : public virtual ShuffleboardValue,
    */
   ComplexWidget& Add(Sendable& sendable);
 
+  /**
+   * Adds a widget to this container to display the given video stream.
+   *
+   * @param video the video to display
+   * @return a widget to display the sendable data
+   * @throws IllegalArgumentException if a widget already exists in this
+   * container with the same title as the video source
+   */
+  ComplexWidget& Add(const cs::VideoSource& video);
+
   /**
    * Adds a widget to this container to display the given data.
    *