Fix: correct JSON parsing in AdminEReportingHeaderController to handle ArrayNode properly

[Manas-Dikshit]

Fix: Correct JSON parsing in AdminEReportingHeaderController

The save() method incorrectly treated reportObligations as an object using fieldNames(),
while getJSON() encodes it as an array. This caused obligations to not be saved properly.

Before:

Iterator<String> it = obligations.fieldNames(); //  ArrayNode has no field names

After:

for (JsonNode obligationNode : obligationsNode) { //  iterate array safely
    String id = obligationNode.path(AQDJSONConstants.ID).asText();
    
}

Properly iterates over ArrayNode
Adds null/invalid ID checks and logging
Fixes data not being persisted during POST

Result: Controller now correctly saves all reporting obligations with stable JSON decoding.