add a prompt library creator/editor

[bghira]

Closes #1838

This pull request introduces a new feature for managing validation prompt libraries, including backend API endpoints, service logic, and frontend integration. It also includes minor CSS adjustments and UI enhancements for modal overlays. The most significant changes are the addition of a prompt library management service and API, updates to the environments tab to support prompt library operations, and improvements to the overall user interface.

Prompt Library Management (Backend):

• Added a new PromptLibraryService in prompt_library_service.py to handle CRUD operations for prompt library JSON files, including validation, normalization, and metadata extraction.
• Introduced a new API router in routes/prompt_libraries.py providing endpoints to list, read, and save prompt libraries, with error handling and data validation.
• Registered the new router in the main FastAPI application setup to expose the endpoints. [1] [2]

Integration with Tab Service and UI Context:

• Updated tab_service.py to load prompt library metadata for the validation and environments tabs, making the data available to the frontend and handling errors gracefully. [1] [2] [3]

Frontend Enhancements (Environments Tab):

• Injected prompt library data into the environments tab template and initialized it for Alpine.js components. [1] [2]
• Added UI logic to load, refresh, and display prompt libraries, including event listeners and modal opening for editing libraries. [1] [2] [3] [4]
• Added a new button and panel in the environments tab for managing validation prompt libraries, improving accessibility and user workflow. [1] [2]

UI and CSS Improvements:

• Updated modal backdrop CSS classes for dataset and training wizards to avoid conflicts and improve z-index stacking. [1] [2] [3]

Other Minor Changes:

• Added a custom_component field for prompt library path selection in validation field registration.
• Minor import adjustments for asdict to support serialization of dataclasses.

These changes collectively enable robust management of validation prompt libraries within the application, enhancing both backend flexibility and frontend usability.