- Refactored BurnPdfCommandHandler to use new extension methods for cleaner annotation handling.
- Introduced ITextStyle interface to generalize font styling for text annotations.
- Updated PDFBurnerParams to implement ITextStyle for consistent font settings reuse.
- Added MathematExtensions for coordinate and unit conversion (ToInches, ToPointF).
- Added GdPictureExtensions to encapsulate annotation-related logic (form fields, images, ink).
- Improved readability and maintainability by removing redundant helper methods.
- add `DefaultIndexOfAnnot` property to provide a fallback index for annotations
- add `GetAnnotationIndex(string name)` method to safely retrieve an annotation index, returning default if not found
- Updated BurnPdfCommandHandler constructor to accept IOptions<PDFBurnerParams> instead of raw PDFBurnerParams.
- Updated AddFormFieldValue to calculate coordinates based on PDFBurnerParams offsets and margins.
- Added helper methods for converting pixels to inches (ToInches, ToPointF).
- Removed unused NotImplemented methods in AddFormFieldValue overload.
- Improved code readability and maintainability for annotation burning logic.
