Save server parameters

[javidahmed64592]

This pull request adds functionality for saving server configuration to a JSON file and improves the flexibility of the server initialization. The main changes include a new method to persist configuration, updates to the server's constructor to allow customization of the API key header name, and new tests to verify the configuration saving feature.

Configuration persistence:

• Added a save_to_file method to the TemplateServerConfig model, enabling saving the configuration as a formatted JSON file.

Server initialization improvements:

• Updated the TemplateServer constructor in template_server.py to accept a customizable api_key_header_name and refactored how configuration and metadata are loaded and stored as instance variables.

Testing:

• Added a test for the new save_to_file method in test_models.py, ensuring that configurations are correctly saved to disk in JSON format.