Enhance API Server-Side Validation for "Signal" Rule Creation

[ethan-haynes]

Problem Description: The current server-side processing of API requests for creating rules in the "Signal" rules engine lacks robust validation for incoming data. This deficiency can lead to issues with improperly formatted or invalid input, ultimately affecting the integrity of the rules and the user experience. To address this, there is a need to improve the server-side API validation to ensure that incoming requests are correctly parsed and that the data adheres to the expected format and constraints.

Proposed Solution: Enhance the server-side API validation for "Signal" rule creation to ensure incoming requests are properly parsed and that the data aligns with the required format and constraints. Implement the following steps:

1. Introduce comprehensive validation checks for incoming API requests, verifying the integrity of the data.
2. Generate clear error responses for invalid input data, ensuring that the requesting user is informed of the issues.
3. Ensure that the server-side API validation aligns with the same expectations as the UI form validation to provide a consistent user experience.

Implementation Steps:

1. Implement server-side validation checks to examine incoming API requests for "Signal" rule creation.
2. Develop a mechanism for generating informative error responses when invalid data is detected.
3. Ensure that the server-side API validation and the UI form validation share a common set of expectations for data input.

Alternatives Considered: N/A

Additional Context: This enhancement aims to enhance the integrity of data processing in the server-side API for "Signal" rule creation. By incorporating robust validation checks and generating informative error responses, this improvement will lead to a more secure and user-friendly experience when creating rules through API requests in GoAlert.

This GitHub issue is created to track the development and implementation of the enhanced server-side API validation for "Signal" rule creation.