fix(input) Write user input only in Normal mode

closes 184

Added the Action::NoOp from
https://github.com/zellij-org/zellij/issues/184

src/common/input/actions.rs

@@ -39,6 +39,8 @@ pub enum Action {
     CloseFocus,
     /// Create a new tab.
     NewTab,
+    /// Do nothing.
+    NoOp,
     /// Go to the next tab.
     GoToNextTab,
     /// Go to the previous tab.

src/common/input/handler.rs

@@ -227,6 +227,7 @@ impl InputHandler {
                     .unwrap();
                 self.command_is_executing.wait_until_pane_is_closed();
             }
+            Action::NoOp => {}
         }
 
         should_break

src/common/input/keybinds.rs

@@ -165,15 +165,16 @@ pub fn key_to_actions(
     mode: &InputMode,
     keybinds: &Keybinds,
 ) -> Vec<Action> {
-    if let Some(mode_keybinds) = keybinds.get(mode) {
-        mode_keybinds
+    let mode_keybind_or_action = |action: Action| {
+        keybinds
+            .get(mode)
+            .unwrap_or_else(|| unreachable!("Unrecognized mode: {:?}", mode))
             .get(key)
             .cloned()
-            // FIXME in command mode, unbound keystrokes should probably do nothing instead of
-            // writing to the terminal. Will be easier to implement after a big refactor of the
-            // input system (@categorille)
-            .unwrap_or_else(|| vec![Action::Write(input)])
-    } else {
-        unreachable!("Unrecognized mode: {:?}", mode);
+            .unwrap_or_else(|| vec![action])
+    };
+    match *mode {
+        InputMode::Normal => mode_keybind_or_action(Action::Write(input)),
+        _ => mode_keybind_or_action(Action::NoOp),
     }
 }