add field content structs

[njausteve]

Title

Add FieldContent Struct with Validation and Update TypedStruct Dependency

Type of Change

• New feature

Description

This pull request adds the typed_struct dependency and introduces the FieldContent struct, which represents a field on a pass. The struct supports attributed values, including optional HTML markup for more dynamic content presentation. A Validators module is added to ensure that attributed values are properly validated, including checks for unsupported HTML tags. Tests are provided to verify struct creation and validation behaviors.

Testing

Tests have been added for:

• Creation of FieldContent structs with different types of attributed values (string, number, DateTime, and Date).
• Validation logic that raises ArgumentError for unsupported types or invalid HTML markup.

Impact

• New Dependency: The project now relies on typed_struct for defining typed structs with defaults.
• Performance: Minor performance overhead due to the added validation logic.
• Security: Improved security with validation for attributed values, particularly with handling HTML content.

Additional Information

No known breaking changes, but reviewers should focus on the HTML validation logic in the Validators module.

Checklist

• My code adheres to the coding and style guidelines of the project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.

[njausteve]

closed: #145