[commands] Revert to original Trigger implementation (#4673)

Trigger was refactored to use BooleanEvent when it was introduced in #4104.
This reverts to the original implementation until edge-based BooleanEvents can be fixed.

wpilibNewCommands/src/test/java/edu/wpi/first/wpilibj2/command/button/TriggerTest.java

@@ -178,7 +178,7 @@ class TriggerTest extends CommandTestBase {
     InternalButton button = new InternalButton();
     Command command1 =
         new StartEndCommand(startCounter::incrementAndGet, endCounter::incrementAndGet)
-            .until(button.rising());
+            .until(button);
 
     button.setPressed(false);
     command1.schedule();