message: Make StarlarkValue require Display
  Summary: We want to have better repr results, since Debug is a pretty poor experience. To do that, make StarlarkValue require Display.
diff: @@ -44,7 +44,7 @@ use std::{
  any::TypeId,
  cell::{Cell, RefCell},
  cmp::Ordering,
  - fmt::{Debug, Write},
  + fmt::{Debug, Display, Write},
  };
  /// Called by the garbage collection, and must walk over every contained `Value` in the type.
  @@ -337,7 +337,7 @@ impl SimpleValue for NoSimpleValue {}
  /// Any additional methods that are added to this trait also need to be added to the
  /// [`StarlarkValue`] implementation in `crate::values::layout::avalue::Wrapper`. Otherwise,
  /// any implementations other than the default implementation will not be run.
  -pub trait StarlarkValue<'v>: 'v + AnyLifetime<'v> + Debug {
  +pub trait StarlarkValue<'v>: 'v + AnyLifetime<'v> + Debug + Display {
  /// Return a string describing the type of self, as returned by the type()
  /// function.
  ///
  