Don't force public variables to use Hungarian notation (#8774)

People generally have expressed a dislike for the Hungarian notation
used in member variables, especially in examples/templates, and our
styleguide shouldn't be forced on downstream consumers, so this removes
all Hungarian notation from the examples/templates.

There are _some_ benefits to Hungarian for private member variables
(like knowing what's a member vs. local in a PR review) so we'll keep
private member variables the same for now, but public variables should
no longer use Hungarian notation, since it looks much worse. A new PMD
XPath rule has been added to accomplish this goal. Some other
non-compliant variables were fixed for the new rule.

cameraserver/multiCameraServer/src/main/java/org/wpilib/Main.java

@@ -49,7 +49,6 @@ import org.wpilib.vision.stream.CameraServer;
 public final class Main {
   private static String configFile = "/boot/CameraServerConfig.json";
 
-  @SuppressWarnings("MemberName")
   public static class CameraConfig {
     public String name;
     public String path;