69 reuse saved jwt auth token until it expire 1

[lukasmatusiewicz]

This pull request includes several changes to the privacyIDEA project, focusing on refactoring the authentication token retrieval process and improving the JSON parsing logic. The most important changes include the introduction of a scheduled task for automatic token retrieval, modifications to the JSONParser class to handle token expiration, and updates to the PIConstants class to include new constants.

Authentication Token Management:

• Added a scheduled task in PrivacyIDEA to automatically retrieve and refresh the authentication token (retrieveAuthToken method).
• Introduced a new CountDownLatch to synchronize token retrieval and added a method to get the token (getAuthToken).

JSON Parsing Enhancements:

• Updated the extractAuthToken method in JSONParser to return a LinkedHashMap with the token and its expiration time.
• Modified the getItemFromAttributes method to simplify the retrieval of WebAuthn sign requests.

Constants Update:

• Added new constants for token expiration and authorization in PIConstants.

Code Cleanup and Refactoring:

• Refactored AsyncRequestCallable to use a final path variable and removed unnecessary code. [1] [2]
• Simplified imports in JSONParser and PIResponse. [1] [2]

Test Adjustments:

• All tests updated!