Add missing `Hash` constraint to `StreamId`

This existed prior to the introduction of the `Host` API, but was lost
in translation. This re-adds the bounds so that downstream code does not
suddenly break due to a lacking `Hash` implementation in the next
CPAL version.

src/platform/mod.rs

@@ -64,7 +64,7 @@ macro_rules! impl_platform_host {
 
         /// The **StreamId** implementation associated with the platform's dynamically dispatched
         /// **Host** type.
-        #[derive(Clone, Debug, Eq, PartialEq)]
+        #[derive(Clone, Debug, Eq, Hash, PartialEq)]
         pub struct StreamId(StreamIdInner);
 
         /// The **SupportedInputFormats** iterator associated with the platform's dynamically
@@ -107,7 +107,7 @@ macro_rules! impl_platform_host {
             )*
         }
 
-        #[derive(Clone, Debug, Eq, PartialEq)]
+        #[derive(Clone, Debug, Eq, Hash, PartialEq)]
         enum StreamIdInner {
             $(
                 $HostVariant(crate::host::$host_mod::StreamId),

src/traits.rs

@@ -195,4 +195,4 @@ pub trait EventLoopTrait {
 }
 
 /// The set of required bounds for host `StreamId` types.
-pub trait StreamIdTrait: Clone + std::fmt::Debug + PartialEq + Eq {}
+pub trait StreamIdTrait: Clone + std::fmt::Debug + std::hash::Hash + PartialEq + Eq {}