Don't show .to_bits in Display impl for Entity (#14011)

accurate for debugging. To ensure that its can still be readily logged
in error messages and inspectors, this PR added a more concise and
human-friendly `Display` impl.

However, users found this form too verbose: the `to_bits` information
was unhelpful and too long. Fixes #13980.

- Don't include `Entity::to_bits` in the `Display` implementation for
`Entity`. This information can readily be accessed and logged for users
who need it.
- Also clean up the implementation of `Display` for `DebugName`,
introduced in https://github.com/bevyengine/bevy/pull/13760, to simply
use the new `Display` impl (since this was the desired format there).

I've updated an existing test to verify the output of `Entity::display`.

---------

Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>

crates/bevy_ecs/src/entity/mod.rs

@@ -392,13 +392,7 @@ impl<'de> Deserialize<'de> for Entity {
 
 impl fmt::Display for Entity {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(
+        write!(f, "{}v{}", self.index(), self.generation())
-            f,
-            "{}v{}|{}",
-            self.index(),
-            self.generation(),
-            self.to_bits()
-        )
     }
 }
 
@@ -1162,9 +1156,7 @@ mod tests {
     fn entity_display() {
         let entity = Entity::from_raw(42);
         let string = format!("{}", entity);
-        let bits = entity.to_bits().to_string();
         assert!(string.contains("42"));
         assert!(string.contains("v1"));
-        assert!(string.contains(&bits));
     }
 }