Add update check and self update option

### Proposed Changes

```console
UPDATE:
   -up, -update                 update shuffledns to the latest version
   -duc, -disable-update-check  disable automatic update check
```

### Reference
- Reference: https://github.com/projectdiscovery/tlsx/blob/8038ac06765d490210aa8bf753f44758a653b39f/cmd/tlsx/main.go#L125
