Update applications.py for UUID bug

[ashtonsyed]

Bug Fix: Ensure UUIDs Are JSON Serializable in Application Creation/Update

Summary

This PR fixes a bug in the Applications._create_or_update method where passing a UUID object directly into the payload results in a TypeError: Object of type UUID is not JSON serializable.
Root Cause

The json.dumps() call fails when it encounters a UUID object. Python's default JSON encoder does not support serializing UUIDs without conversion.
Fix

Wrapped UUID values with str() to ensure compatibility with json.dumps(). Specifically updated lines ≈88-90

From:

if business_unit != None:
    bu = {'business_unit': {'guid': business_unit}}
    app_def.update(bu)

To:

if business_unit != None:
    bu = {'business_unit': {'guid': str(business_unit)}}
    app_def.update(bu)

Context

The issue manifests when calling create() or update() with a UUID provided for business_unit, policy_guid, or similar fields. Without this fix, valid requests can raise runtime exceptions and block automation pipelines relying on these methods.

Testing

Manually tested with UUID inputs for business_unit and policy_guid.

Confirmed that json.dumps() succeeds and payloads are correctly formatted.

Applications were successfully created/updated via the API.

Notes

There may be other locations in the codebase where UUIDs are passed into JSON payloads; recommend a broader audit to ensure consistent serialization.