[FEATURE] Rename default operation to match-all operation in all workloads

[IanHoang]

Reword default operations to match-all to be more concise. For each workload, we will need to update the operation mentioned in test_procedures/default.json and operations/default.json

test_procedures/default.json

        {
          "operation": "default",
          "warmup-iterations": 50,
          "iterations": 100
          {%- if not target_throughput %}
          ,"target-throughput": 3
          {%- elif target_throughput is string and target_throughput.lower() == 'none' %}
          {%- else %}
          ,"target-throughput": {{ target_throughput | tojson }}
          {%- endif %}
          {%-if search_clients is defined and search_clients %}
          ,"clients": {{ search_clients | tojson}}
          {%- endif %}
        },

operations/default.json

    {
      "name": "default",
      "operation-type": "search",
      "body": {
        "query": {
          "match_all": {}
        }
      }
    },