- fixed issue with messages in policy.proto and context-policy.proto
- modified and unified script to generate Python code from proto files
- segregated script to generate UML code
- added/modified apropriate .gitignore files to prevent uploading generated code. It should be generated locally or during creation of Docker containers
- added symbolic link from common/proto to folder containing python generated code

PolicyAdd rpc replaced by PolicyAddService & PolicyAddDevice

ACL:
- defined generic model for ACLs

Context:
- Extended context.proto with ConnectionSettings
- Extended context.proto with ConfigRules specific for ACLs
Extended context.proto with Constraints for Schedule, Location, and SLAs
- created ContextPolicy to bring persistent storage of policies
- updated genproto.sh

Policy:
- added missing message to list PolicyRuleIds

- restructured component and separated it into "connector" and "gateway" subcomponents.
- arranged name typos in DLT proto file
- prepared component folders for dlt-connector component

- Defined new dlt.proto file

Updated gRPC proto files to prevent trouble with KPI sample types in devices, also updated files related to this issue.