Refactor API specification resource for clarity and consistency

- Consolidated the long API specification description into a global
  constant for improved readability.
- Renamed `apiSpecificationResource` to `apiSpecResource` and updated
  related structs and methods for consistency.
- Replaced `jsonMatch` function with a more robust implementation.
- Improved error handling and logging across the resource methods.
- Added `TestJsonMatch` unit tests to validate the JSON comparison
  logic.
- General cleanup and code structure improvements for maintainability.

Author: joshbeard