Add local context methods to Context.php; enhance key management functionality

Author: EdmondDantes

examples/Async/Context.php

@@ -8,7 +8,11 @@ final class Context
 {
     public function find(string|object $key): mixed {}
     public function get(string|object $key): mixed {}
+    public function has(string|object $key): bool {}
     public function set(string|object $key, mixed $value, bool $replace = false): self {}
     public function unset(string|object $key): self {}
+    public function findLocal(string|object $key): mixed {}
+    public function getLocal(string|object $key): mixed {}
+    public function hasLocal(string|object $key): bool {}
     public function dispose(): void {}
 }