refactor: derive Eq, Hash and Copy for View

To use as a key in a hashmap, a type must implement `Eq` and `Hash`.
Additionally, `Copy` is required as well to be used in the .entry()
method of Hashmap.

Derive `Eq`, `Copy` and `Hash` on View to use it as a key in Hashmaps.

Signed-off-by: Ivin Joel Abraham <[email protected]>

Author: ivinjabraham

src/model/screens/mod.rs

@@ -4,7 +4,7 @@ pub mod edit_config;
 pub mod latest;
 pub mod mail_list;
 
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Copy, Debug, Clone, PartialEq, Eq, Hash)]
 pub enum View {
     MailingListSelection,
     BookmarkedPatchsets,