Remove the sourceObjects field from the JobCollections index

[006627]

The sourceObjects field stores information about the objects to be affected by a process, which can either be a search query or a list of object identifiers. However, when large lists of identifiers are provided, Solr can become overloaded while processing the document. This overload may degrade the system's performance, disrupt the search service, and, in some cases, leave RODA unresponsive.

Removing this field from the JobCollections index aims to address these issues, improving the system's scalability and stability.

When removing this field, it is essential to identify and adjust any areas in the interface that depend on it. Wherever necessary, RODA should retrieve information about the selected objects directly from the model instead of the index. Additionally, it may be necessary to split the Job class into two distinct classes to differentiate between objects originating from the model and those retrieved from the index.