remove double referencing

Reasons:
- The compiler will immediately dereference the referenced reference.

Signed-off-by: Perma Alesheikh <me@prma.dev>

src/folder/command/create.rs

@@ -72,7 +72,7 @@ impl AddFolderCommand {
         )
         .await?;
 
-        backend.add_folder(&folder).await?;
+        backend.add_folder(folder).await?;
 
         printer.print(format!("Folder {folder} successfully created!"))
     }

src/folder/command/delete.rs

@@ -87,7 +87,7 @@ impl FolderDeleteCommand {
         )
         .await?;
 
-        backend.delete_folder(&folder).await?;
+        backend.delete_folder(folder).await?;
 
         printer.print(format!("Folder {folder} successfully deleted!"))
     }

src/folder/command/expunge.rs

@@ -76,7 +76,7 @@ impl FolderExpungeCommand {
         )
         .await?;
 
-        backend.expunge_folder(&folder).await?;
+        backend.expunge_folder(folder).await?;
 
         printer.print(format!("Folder {folder} successfully expunged!"))
     }

src/folder/command/purge.rs

@@ -86,7 +86,7 @@ impl FolderPurgeCommand {
         )
         .await?;
 
-        backend.purge_folder(&folder).await?;
+        backend.purge_folder(folder).await?;
 
         printer.print(format!("Folder {folder} successfully purged!"))
     }