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.

wpilibj/src/main/java/org/wpilib/counter/EdgeConfiguration.java

@@ -12,7 +12,6 @@ public enum EdgeConfiguration {
   FALLING_EDGE(false);
 
   /** True if triggering on rising edge. */
-  @SuppressWarnings("MemberName")
   public final boolean rising;
 
   EdgeConfiguration(boolean rising) {