Fix type preservation for nested interface pointers

[wesen]

Fixes issues with type handling when dealing with nested interface{} and pointer
types by:

• Modify StripInterface to preserve pointer types while stripping interface wrappers
• Add NormalizeValue function to handle type comparison and normalization
• Fix parameter validation to properly handle object lists

Key changes:

• StripInterface now returns *T instead of T for pointer types
• Object lists are properly typed as []map[string]interface{}
• Added value normalization for consistent comparisons
• Better handling of nil values and defaults

The changes ensure proper type preservation when dealing with interface{} wrapped
pointer types, fixing several edge cases around parameter handling and validation.