Refactor in Analytics, Telemetry, and KpiManager Services and Manifest Files to Reflect Generic DB Changes.

- Improvements made to `tfs.sh` script.
- Added `CRDB_DATABASE` environment variable to all monitoring service manifest files and the context manifest file.
- Removed the DB engine file from all monitoring services and moved it to `common.tools.database`.
- Each `<service_name>_DB.py` will now retrieve the database name from the environment variable.