* Add cluster deletion and completion enhancements
- Implemented `--all` flag for deleting all clusters in a namespace.
- Updated argument parsing to allow for maximum one cluster name.
- Added completion functions for cluster names with namespace filtering.
- Enhanced tests for cluster argument resolution and completion functions.
* fix docs
* Add log message for empty cluster deletion in specified namespace
* Refactor context handling in command functions to use `cmd.Context()`
* Add completion to `--namespace` flag
* Add namespace completion to policy create command
* Refactor namespace completion functions for consistency across commands
* addressed some comments
- Refactor createFlags function to return an error for better error handling.
- Add flag completion functions for cluster mode and persistence type.
- Implement disableFileCompletion to prevent default filename completions.
- Register flag completion for mode in NewPolicyCreateCmd.
Enrico CandinoandGitHub