flux-account-priority-update: use column names

Problem: The flux-account-priority-update script uses row indexes to
build the data that is sent to the priority plugin, but this is
problematic because it relies on internal knowledge of the DB schema
and it is unreadable.

Use the conn.row_factory property to access row values by column name
instead of by index.

src/cmd/flux-account-priority-update.py

@@ -67,6 +67,7 @@ def est_sqlite_conn(path):
 
 def bulk_update(path):
     conn = est_sqlite_conn(path)
+    conn.row_factory = sqlite3.Row
     cur = conn.cursor()
 
     data = {}
@@ -83,18 +84,18 @@ def bulk_update(path):
     ):
         # create a JSON payload with the results of the query
         single_user_data = {
-            "userid": int(row[0]),
-            "bank": str(row[1]),
-            "def_bank": str(row[2]),
-            "fairshare": float(row[3]),
-            "max_running_jobs": int(row[4]),
-            "max_active_jobs": int(row[5]),
-            "queues": str(row[6]),
-            "active": int(row[7]),
-            "projects": str(row[8]),
-            "def_project": str(row[9]),
-            "max_nodes": int(row[10]),
-            "max_cores": int(row[11]),
+            "userid": int(row["userid"]),
+            "bank": str(row["bank"]),
+            "def_bank": str(row["default_bank"]),
+            "fairshare": float(row["fairshare"]),
+            "max_running_jobs": int(row["max_running_jobs"]),
+            "max_active_jobs": int(row["max_active_jobs"]),
+            "queues": str(row["queues"]),
+            "active": int(row["active"]),
+            "projects": str(row["projects"]),
+            "def_project": str(row["default_project"]),
+            "max_nodes": int(row["max_nodes"]),
+            "max_cores": int(row["max_cores"]),
         }
         bulk_user_data.append(single_user_data)
 
@@ -106,11 +107,11 @@ def bulk_update(path):
     for row in cur.execute("SELECT * FROM queue_table"):
         # create a JSON payload with the results of the query
         single_q_data = {
-            "queue": str(row[0]),
-            "min_nodes_per_job": int(row[1]),
-            "max_nodes_per_job": int(row[2]),
-            "max_time_per_job": int(row[3]),
-            "priority": int(row[4]),
+            "queue": str(row["queue"]),
+            "min_nodes_per_job": int(row["min_nodes_per_job"]),
+            "max_nodes_per_job": int(row["max_nodes_per_job"]),
+            "max_time_per_job": int(row["max_time_per_job"]),
+            "priority": int(row["priority"]),
         }
         bulk_q_data.append(single_q_data)
 
@@ -122,7 +123,7 @@ def bulk_update(path):
     for row in cur.execute("SELECT project FROM project_table"):
         # create a JSON payload with the results of the query
         single_project = {
-            "project": str(row[0]),
+            "project": str(row["project"]),
         }
         bulk_proj_data.append(single_project)