Fix keys getting swallowed when enabling only "Report event types"

Per kovidgoyal/kitty#9999, enabling "Report event types" without
"Disambiguate escape codes" doesn't really make sense, and terminals may
choose whatever behavior they think makes sense. However, keys shouldn't
get swallowed (which, after #5791, happens when the !useCsiU branch
cannot handle the event), so instead make "Report event types" imply
"Disambiguate escape codes".

src/common/input/KittyKeyboard.test.ts

@@ -478,7 +478,7 @@ describe('KittyKeyboard', () => {
         assert.strictEqual(result.key, '\x7f');
       });
 
-      it('press event explicit :1 when modifiers present', () => {
+      it('press event when modifiers present', () => {
         const result = kitty.evaluate(createEvent({ key: 'a', ctrlKey: true }), flags, KittyKeyboardEventType.PRESS);
         assert.strictEqual(result.key, '\x1b[97;5u');
       });
@@ -554,6 +554,27 @@ describe('KittyKeyboard', () => {
       });
     });
 
+    // Enabling REPORT_EVENT_TYPES without DISAMBIGUATE_ESCAPE_CODES doesn't really make sense and
+    // isn't specified in the spec, but press and repeat events shouldn't get swallowed.
+    describe('REPORT_EVENT_TYPES flag without DISAMBIGUATE_ESCAPE_CODES', () => {
+      const flags = KittyKeyboardFlags.REPORT_EVENT_TYPES;
+
+      it('press event is not swallowed when modifiers present', () => {
+        const result = kitty.evaluate(createEvent({ key: 'a', ctrlKey: true }), flags, KittyKeyboardEventType.PRESS);
+        assert.strictEqual(result.key, '\x1b[97;5u');
+      });
+
+      it('repeat event is not swallowed when modifiers present', () => {
+        const result = kitty.evaluate(createEvent({ key: 'a', ctrlKey: true }), flags, KittyKeyboardEventType.REPEAT);
+        assert.strictEqual(result.key, '\x1b[97;5:2u');
+      });
+
+      it('release event is reported as CSI u sequence', () => {
+        const result = kitty.evaluate(createEvent({ key: 'a', ctrlKey: true }), flags, KittyKeyboardEventType.RELEASE);
+        assert.strictEqual(result.key, '\x1b[97;5:3u');
+      });
+    });
+
     describe('modifier-only reporting', () => {
       const flags = KittyKeyboardFlags.REPORT_EVENT_TYPES;