Make web::Path innards public

So we can do something like this:
```
async fn delete_channel_message(
    web::Path((channel_id, message_id)): web::Path<(Snowflake, Snowflake)>,
) {
  // here channel_id and message_id are Snowflakes,
  // and not web::Path<Snowflake>
}
```

Dunno why other web types are public and this is not.

actix-web/CHANGES.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Make contents of `web::Path` public.
+
 ## 4.9.0
 
 ### Added

actix-web/src/types/path.rs

@@ -54,7 +54,7 @@ use crate::{
 /// }
 /// ```
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Deref, DerefMut, AsRef, Display, From)]
-pub struct Path<T>(T);
+pub struct Path<T>(pub T);
 
 impl<T> Path<T> {
     /// Unwrap into inner `T` value.