fix(search): allow terminating char to clear search term (#1853)

* allow terminating char to clear search term

* format code

zellij-server/src/tab/mod.rs

@@ -2650,8 +2650,10 @@ impl Tab {
 
     pub fn update_search_term(&mut self, buf: Vec<u8>, client_id: ClientId) -> Result<()> {
         if let Some(active_pane) = self.get_active_pane_or_floating_pane_mut(client_id) {
-            // It only allows printable unicode, delete and backspace keys.
-            let is_updatable = buf.iter().all(|u| matches!(u, 0x20..=0x7E | 0x08 | 0x7F));
+            // It only allows terminating char(\0), printable unicode, delete and backspace keys.
+            let is_updatable = buf
+                .iter()
+                .all(|u| matches!(u, 0x00 | 0x20..=0x7E | 0x08 | 0x7F));
             if is_updatable {
                 let s = str::from_utf8(&buf).with_context(|| {
                     format!("failed to update search term to '{buf:?}' for client {client_id}")