Fix processor saving with multiple tokenizers
Author: ManishhDev
Pull request: yes

Resolves issue #41816

When a processor contains multiple tokenizers (or other sub-processors of the same type), they were overwriting each other during save due to using the same file names. This fix:

1. Saves each attribute in its own subdirectory named after the attribute name
2. Updates loading logic to check for subdirectories first (new format), then falls back to main directory (legacy format) for backward compatibility

This maintains backward compatibility while allowing processors with multiple tokenizers to save and load correctly.

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