Add reason and message properties to job execution response

[bhanuprakash-1]

Adding high level reason and message in job execution response to provide better diagnostics and status information for job executions.

Changes Made

This PR adds two new read-only properties to the JobExecution definition in the 2025-10-02-preview API version:

• reason: A string property that provides the reason for the current condition of the job execution
• message: A human-readable string message indicating details about the current condition of the job execution

Files Modified

1. Jobs.json - Added schema definitions for reason and message properties
2. Job_Execution_Get.json - Updated example to include reason and message
3. Job_Executions_Get.json - Updated example to include reason and message
4. Job_Stop_Multiple.json - Updated example to include reason and message

Example Values

"reason": "BackoffLimitExceeded",
"message": "Job has reached the specified backoff limit"

These properties align with the server-side implementation and provide better visibility into job execution status.

[github-actions]

Next Steps to Merge

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  This PR is awaiting ARM reviewer feedback (label: WaitForARMFeedback).
  To learn when this PR will get reviewed, see ARM review queue at aka.ms/azsdk/pr-arm-review
  For details of the ARM review, see aka.ms/azsdk/pr-arm-review
  

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[github-actions]

API Change Check

APIView identified API level changes in this PR and created the following API reviews

Language	API Review for Package
Go	sdk/resourcemanager/appcontainers/armappcontainers
Java	com.azure.resourcemanager:azure-resourcemanager-appcontainers
JavaScript	@azure/arm-appcontainers