- extend load generator status with num_released requests

- extend load generator with max number of workers

- extend load generator with service constraints (availability, capacity and latency)

- implemented enhanced methods to control load generator form WebUI

- Added/Updated headers
- Added script to update copyright headers

- Converted load_gen tool into a microservice
- Added simple WebUI page to manage it
- Created manifests, Dockerfile, etc.
- Created proto file to manage the load generator

- Arranged commit before merge
- Replaced string-based timestamps by context.Timestamp
- Created helper functions to convert timestamps string from/to float
- Arranged requirements to meet dependencies of converter functions