Implement kitty's keyboard protocol

The protocol enables robust key reporting for the applications, so
they could bind more keys and the user won't have collisions with
the normal control keys.

Links: https://sw.kovidgoyal.net/kitty/keyboard-protocol
Fixes #6378.

CHANGELOG.md

@@ -27,6 +27,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - `window.blur` config option to request blur for transparent windows
 - `--option` argument for `alacritty msg create-window`
 - Support for `DECRQM`/`DECRPM` escape sequences
+- Support for kitty's keyboard protocol
 
 ### Changed
 

alacritty/src/config/ui_config.rs

@@ -10,14 +10,15 @@ use log::{error, warn};
 use serde::de::{Error as SerdeError, MapAccess, Visitor};
 use serde::{self, Deserialize, Deserializer};
 use unicode_width::UnicodeWidthChar;
-use winit::keyboard::{Key, KeyLocation, ModifiersState};
+use winit::keyboard::{Key, ModifiersState};
 
 use alacritty_config_derive::{ConfigDeserialize, SerdeReplace};
 use alacritty_terminal::term::search::RegexSearch;
 
 use crate::config::bell::BellConfig;
 use crate::config::bindings::{
-    self, Action, Binding, BindingKey, KeyBinding, ModeWrapper, ModsWrapper, MouseBinding,
+    self, Action, Binding, BindingKey, KeyBinding, KeyLocation, ModeWrapper, ModsWrapper,
+    MouseBinding,
 };
 use crate::config::color::Colors;
 use crate::config::cursor::Cursor;
@@ -152,11 +153,12 @@ impl UiConfig {
     /// Derive [`TermConfig`] from the config.
     pub fn term_options(&self) -> TermConfig {
         TermConfig {
+            semantic_escape_chars: self.selection.semantic_escape_chars.clone(),
             scrolling_history: self.scrolling.history() as usize,
-            default_cursor_style: self.cursor.style(),
             vi_mode_cursor_style: self.cursor.vi_mode_style(),
-            semantic_escape_chars: self.selection.semantic_escape_chars.clone(),
+            default_cursor_style: self.cursor.style(),
             osc52: self.terminal.osc52.0,
+            kitty_keyboard: true,
         }
     }