fix: Correctly propage user arguments to Spark connect server

[sbernauer]

Description

A customer asked me how to do Iceberg with a SparkConnect server. So I tried and noticed this bug.
Added a kuttl test as well.

From

  - args:                                                                                                                                                                                                          
    - |-                                                                                                                                                                                                           
      containerdebug --output=/stackable/log/containerdebug-state.json --loop &                                                                                                                                    
                                                                                                                                                                                                                   
      cp /stackable/spark/conf/spark-defaults.conf /tmp/spark.properties                                                                                                                                           
      config-utils template /tmp/spark.properties                                                                                                                                                                  
                                                                                                                                                                                                                   
      /stackable/spark/sbin/start-connect-server.sh \                                                                                                                                                              
      --deploy-mode client \                                                                                                                                                                                       
      --master k8s://https://${KUBERNETES_SERVICE_HOST}:${KUBERNETES_SERVICE_PORT_HTTPS} \                                                                                                                         
      --properties-file /tmp/spark.properties                                                                                                                                                                      
       --package org.apache.iceberg:iceberg-spark-runtime-4.1_2.13:1.11.0 

to

  - args:                                                                                                                                                                                                          
    - |-                                                                                                                                                                                                           
      containerdebug --output=/stackable/log/containerdebug-state.json --loop &                                                                                                                                    
                                                                                                                                                                                                                   
      cp /stackable/spark/conf/spark-defaults.conf /tmp/spark.properties                                                                                                                                           
      config-utils template /tmp/spark.properties                                                                                                                                                                  
                                                                                                                                                                                                                   
      /stackable/spark/sbin/start-connect-server.sh \                                                                                                                                                              
      --deploy-mode client \                                                                                                                                                                                       
      --master k8s://https://${KUBERNETES_SERVICE_HOST}:${KUBERNETES_SERVICE_PORT_HTTPS} \                                                                                                                         
      --properties-file /tmp/spark.properties \                                                                                                                                                                    
      --packages org.apache.iceberg:iceberg-spark-runtime-4.1_2.13:1.11.0

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Author

• Changes are OpenShift compatible
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Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
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• Links to generated (nightly) docs added
• Release note snippet added
• Add type/deprecation label & add to the deprecation schedule
• Add type/experimental label & add to the experimental features tracker

[razvan]

thanks!