Allow suffix and prefix

[ecarreras]

This pull request includes several changes to enhance the handling of widget_props across different components and to improve the parsing of widget properties. The most important changes include the addition of new getter methods in the Field class, updates to the Form class to merge widget properties, and the creation of a new utility function for parsing widget properties.

Enhancements to widget_props handling:

• src/Field.ts: Added suffix and prefix getter methods to the Field class to retrieve widget properties.

• src/Form.ts: Updated imports to include parseWidgetProps and modified the Form class to merge widget_props from the fields definition and XML attributes. [1] [2]

• src/Widget.ts: Updated the Widget class to use the new parseWidgetProps utility function for parsing widget_props. [1] [2]

Utility function creation:

• src/helpers/attributeParser.ts: Added a new parseWidgetProps function to handle the parsing of widget_props from both strings and objects.

Testing improvements:

• src/spec/Form.spec.ts: Added a new test case to ensure that widget_props from fields definition and XML attributes are correctly merged.