Make policy path configurable

[lhilton]

My current application requires the policies for filament to be stored in another location than default. This PR makes the policy path configurable.

[what-the-diff]

PR Summary

• Introduced flexible policy path configuration
  This change allows to specify the path of the policies in the config/filament-shield.php file. Now, instead of the path being hardcoded, you can set it as you prefer.

• Updated policy path handling in file generation
  It also modifies certain methods in the src/Commands/Concerns/CanGeneratePolicy.php file. There is no longer a hardcoded policy path string. Instead, the path will be dynamically generated based on the path prefix set in the configuration. This leads to improved flexibility and customization for your project.

[bezhanSalleh]

neat, thanks!