REF: Refactor converter and address duplicate code bugs

[YektaY]

Description

1. Bug fixes: Fixed duplicate Font.family attribute, duplicate Str.to_xml() list check, duplicate Alignment.to_xml() mapping block, duplicate XMLConvertible.secretId. Fixed hidden_widgets bug where "activechoicebuttonclass, activextextclass" was a single comma-separated string that never matched. Replaced all stray print()/breakpoint() calls with logger across 6 files
2. Break up large convert_edm_to_pydm_widgets in into resolve_widget_type(), convert_attribute_value(), apply_widget_post_processing(), and promoted traverse_group() to top-level.
3. Merged create_off_button() and create_freeze_button() into shared create_button_variant()
4. Error handling: Added pydmconverter/exceptions.py with ConverterError, UnsupportedWidgetError, AttributeConversionError, ColorConversionError. Wired AttributeConversionError into attribute setting for better debug context