message: Add Serialize for [Frozen]ValueTyped
  Summary: Useful instances to have.
diff: @@ -29,6 +29,7 @@ use gazebo::{
  coerce::{Coerce, CoerceKey},
  prelude::*,
  };
  +use serde::Serialize;
  use crate::{
  gazebo::any::AnyLifetime,
  @@ -96,6 +97,24 @@ impl<'v, T: StarlarkValue<'v>> Display for FrozenValueTyped<'v, T> {
  }
  }
  +impl<'v, T: StarlarkValue<'v>> Serialize for ValueTyped<'v, T> {
  + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
  + where
  + S: serde::Serializer,
  + {
  + self.0.serialize(serializer)
  + }
  +}
  +
  +impl<'v, T: StarlarkValue<'v>> Serialize for FrozenValueTyped<'v, T> {
  + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
  + where
  + S: serde::Serializer,
  + {
  + self.0.serialize(serializer)
  + }
  +}
  +
  impl<'v, T: StarlarkValue<'v>> ValueTyped<'v, T> {
  /// Downcast.
  pub fn new(value: Value<'v>) -> Option<ValueTyped<'v, T>> {
  