Switching telemetry datasource from SQLite to PosgreSQL

After migration from Grafana's SQLite to PostgreSQL the datasource should be disabled or removed (to be decided).

tlemetry datasource: GRAFANADB_SELECT should be replaced with PMMDB_SELECT (if destination database will be postgre/pmm) and excluded from telemetry in config file.

UI/UX:

Acceptance criteria:

• disabled/removed GRAFANADB_SELECT telemetry datasource

• telemetry data in clickhouse db should contain data from PostgreSQL database

Out of scope:

• Migration database from SQLite to PostgreSQL

How can we test that telemetry works correctly with PostgreSQL?
Data should be populated in CH database.  SQL resoult should not be empty:

or