[Core] Add Repeat Key ("repeat last key") as a core feature. (#19700)

Co-authored-by: casuanoob <[email protected]>
Co-authored-by: Sergey Vlasov <[email protected]>

data/constants/keycodes/keycodes_0.0.3_quantum.hjson

@@ -0,0 +1,18 @@
+{
+    "keycodes": {
+       "0x7C79": {
+            "group": "quantum",
+            "key": "QK_REPEAT_KEY",
+            "aliases": [
+                "QK_REP"
+            ]
+        },
+        "0x7C7A": {
+            "group": "quantum",
+            "key": "QK_ALT_REPEAT_KEY",
+            "aliases": [
+                "QK_AREP"
+            ]
+        }
+    }
+}