Allow copilot-cli to write via tool to only specific files

### Describe the feature or problem you'd like to solve

When the copilot write tool option is allowed it gives access to all files

### Proposed solution

Allow to restrict the scope the model is allowed to write to, for example with directories or files
```bash
copilot --allow-tool 'write(foo.txt)' --allow-tool 'write(bar/)'
```

This is similar to the shell tool option that is already supported https://docs.github.com/en/copilot/concepts/agents/about-copilot-cli#using-the-approval-options
```
copilot --deny-tool 'shell(git push)'
```

### Example prompts or workflows

```bash
copilot --allow-tool 'write(foo.txt)' --allow-tool 'write(bar/)'
```

### Additional context

_No response_