- testing session management

- corrected retrieval of context/topology names

- extneded context selection to context/topology
- enabled selection of context/topology to plot
- enabled listing of devices/links based on context/topology
- updated network icon

- Moved imports from *.proto folder to common.proto folder
- Removed webui's genproto.sh script
- Minor code and linting fixing
- Arranged requirements to accelerate Docker image creation
- Updated Dockerfile
- Arranged GitLab CI/CD pipeline
- Corrected usage of ConfigRules to use new custom ConfigRules
- Moved config variables to new config framework
- Removed unneeded Config variables

- removed hardcoded paths and replaced by url_for methods
- arranged service paths to be homogeneous with other entities
- implemented service delete
- adapted JavaScript scripts to use dynamically generated paths from Jinja
- corrected error logger in delete of device and service
- implemented logic to support deploying the WebUI on a subpath of WSGI servers

Implementing refinements in the webui: dividing forms for selecting the context and uploading json files in the home page; listing and detailing existing services.