Added Executor

[RohitKushvaha01]

This PR adds an Executor plugin that allows executing shell commands in Acode without requiring Termux.

Example usage:

Executor.exec(
    "echo hello",
    (stdout) => {
        console.log("Executor output: " + stdout);
    },
    (error) => {
        console.warn("Executor error: " + error);
    }
);

---

⚠️ Limitations

1. No W^X support:
   Starting from Android 9, files with both write and execute permissions (W^X) are no longer allowed. As a result, binary files in internal storage cannot be executed directly.

   • ✅ Workaround: You can use /system/bin/linker or /system/bin/linker64 to load and execute non-static binaries, but this only works if the binary is outside internal storage and is dynamically linked.

2. Shells are not fully supported:
   You can execute shell scripts using shell interpreters (like sh or bash), but do not execute the shell directly (e.g., just "sh"), as it will hang. shells remain active and wait for input until explicitly terminated via Ctrl+C or a kill signal.