addd partial counts to SPHN Connector Overview Dashboard

Adds "real_time_counts" to the sphn connector overview dashboard in Grafana.

• new pipeline run_grafana_count (scheduled to run every five minutes). DAG is not activate as a default.
• added start & stop tasks to different steps: PreCheck&De-ID, Integration, validation and statistics
• data is saved in new table in the postgres database: grafana_real_time_report
• after the 'main' tasks have finished for integration / validation a last update from the pipeline_history is made to extract the total amount of patients processed
• feature not added for the landing zone Graphic since the update of the landing_zone table is faster than the periodic update of the grafana_real_time_report table

Old visual:

New visual: The number of patients will "move" through the different zones as they progress in the Connector.

Short summary:

• update Airflow version to 2.9.0
• adds new DAG: run_grafana_count
• updates sphn connector overview Dashboard
• adds new module grafana_counts.py
• new table in postgres: grafana_real_time_report

Let me know what you think. @nicola.stoira @philip.krauss