chore: align dataset summary output (#4541)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
	- Enhanced test size configuration with percentage-based input
	- Added method to automatically compute test sizes across systems

- **Deprecation**
	- Marked `get_test` method as deprecated

- **Improvements**
	- Updated logging format for better readability
	- Improved error handling for test size configuration

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: caic99

deepmd/utils/data_system.py

@@ -675,7 +675,7 @@ def print_summary(
     )
     for ii in range(nsystems):
         log.info(
-            "%s %6d %6d %6d %9.3e %3s",
+            "%s  %6d  %6d  %6d  %9.3e  %3s",
             _format_name_length(system_dirs[ii], sys_width),
             natoms[ii],
             batch_size[ii],