Move logic for ingest benchmark from GitHub workflow into python testcase (#9762)

## Problem

The first version of the ingest benchmark had some parsing and reporting
logic in shell script inside GitHub workflow.
it is better to move that logic into a python testcase so that we can
also run it locally.

## Summary of changes

- Create new python testcase
- invoke pgcopydb inside python test case
- move the following logic into python testcase
  - determine backpressure
  - invoke pgcopydb and report its progress
  - parse pgcopydb log and extract metrics
  - insert metrics into perf test database
 
- add additional column to perf test database that can receive endpoint
ID used for pgcopydb run to have it available in grafana dashboard when
retrieving other metrics for an endpoint

## Example run


https://github.com/neondatabase/neon/actions/runs/11860622170/job/33056264386

scripts/ingest_perf_test_result.py

@@ -25,7 +25,8 @@ CREATE TABLE IF NOT EXISTS perf_test_results (
     metric_value NUMERIC,
     metric_unit VARCHAR(10),
     metric_report_type TEXT,
-    recorded_at_timestamp TIMESTAMP WITH TIME ZONE DEFAULT NOW()
+    recorded_at_timestamp TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    labels JSONB with default '{}'
 )
 """
 
@@ -91,6 +92,7 @@ def ingest_perf_test_result(cursor, data_file: Path, recorded_at_timestamp: int)
                 "metric_unit": metric["unit"],
                 "metric_report_type": metric["report"],
                 "recorded_at_timestamp": datetime.utcfromtimestamp(recorded_at_timestamp),
+                "labels": json.dumps(metric.get("labels")),
             }
             args_list.append(values)
 
@@ -105,7 +107,8 @@ def ingest_perf_test_result(cursor, data_file: Path, recorded_at_timestamp: int)
             metric_value,
             metric_unit,
             metric_report_type,
-            recorded_at_timestamp
+            recorded_at_timestamp,
+            labels
         ) VALUES %s
         """,
         args_list,
@@ -117,7 +120,8 @@ def ingest_perf_test_result(cursor, data_file: Path, recorded_at_timestamp: int)
             %(metric_value)s,
             %(metric_unit)s,
             %(metric_report_type)s,
-            %(recorded_at_timestamp)s
+            %(recorded_at_timestamp)s,
+            %(labels)s
         )""",
     )
     return len(args_list)