feat(header): implement fmt::Display for several headers

Specifically, `CacheControl`, `Expect`, `Origin`, `Pragma`, `Prefer`,
`PreferenceApplied`, `ReferrerPolicy`, `StrictTransportSecurity`.

src/header/common/origin.rs

@@ -59,7 +59,7 @@ impl Header for Origin {
     }
 
     fn fmt_header(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}://{}", self.scheme, self.host)
+        fmt::Display::fmt(self, f)
     }
 }
 
@@ -83,6 +83,12 @@ impl FromStr for Origin {
     }
 }
 
+impl fmt::Display for Origin {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}://{}", self.scheme, self.host)
+    }
+}
+
 impl PartialEq for Origin {
     fn eq(&self, other: &Origin) -> bool {
         self.scheme == other.scheme && self.host == other.host