Fetch compound document

[leoraba]

Description

This PR introduces a new feature to this project - View representation of a compound document represented in a hierarchical structure of related Submitted Data, consolidating all related data for a central entity, or centric schema, while organizing both its parent and child relationships within the document. This structure will enable more efficient data access by aggregating connected data into a single view.

Here's how each relationships are represented:

• Centric Schema: The central entity is the focal point of the document. All related data, including both parent and child records, is organized around this entity.
• Child entities: Displayed in arrays within the centric schema document. Each child entry includes relevant information and may also contain an array of its own children allowing for a nested, hierarchical structure.
• Parent entity: representing the entity to which the centric entity belongs, is stored as a single, unique field within the centric schema document.

Code changes:

• Changes on existing GET data endpoints to add a query parameter view. This specify the data representation to be returned. Use list to return an unordered list of entities; compound to return a compound document nesting using scheme centric structure.
• Change on register new Dictionary endpoint to include new body parameter defaultCentricEntity. This value is used to form compound documents.
• New environment variables: NESTED_RECORD_PREFIX, NESTED_RECORD_SUFFIX, PARENT_RECORD_PREFIX, PARENT_RECORD_SUFFIX
• Add new GET data by systemID endpoint.

[leoraba]

PR updated. Fixed typos and replied to comments.