utils/log: maintain indent for buffered records
utils/log: maintain indent for buffered records

Ensure buffered records are indented properly by saving the indent level
at the time the record was generated as part of the record, and
preferring that over the current indent level inside LineFormatter.

ARM-software/workload-automation,ARM-software/workload-automation,lisatn/workload-automation,lisatn/workload-automation,lisatn/workload-automation,ARM-software/workload-automation,setrofim/workload-automation,setrofim/workload-automation,ARM-software/workload-automation,lisatn/workload-automation,setrofim/workload-automation,setrofim/workload-automation