Merge in XRCA/teraflow from vhallivu/XR_OPTICS_DRIVER_LOGIN_TO_CM to xr_development

Squashed commit of the following:

commit ba53d51d94c52491c4f70587187bf6746a9613da
Author: Ville Hallivuori <VHallivuori@infinera.com>
Date:   Fri Aug 5 13:26:40 2022 +0300

    Initial code for XR Device Driver, can connect to CM and acquire access token. No other functionality

- Slice: added config rules
- Added EndpointPriority constraint
- Modified IsolationLevel constraint to contain a repetition of items

- Arranged .gitignore & .gitkeep files in common proto folder
- Created specific run_tests_locally script for Context component
- Moved imports from *.proto folder to common.proto folder
- Adapted common.tools.object_factory to new proto definitions for ConfigRule and Constraint
- Extended common.tools.type_checkers to new proto definitions for ConfigRule and Constraint
- Removed context's genproto.sh script
- Adapted Events generated to new timestamp data type
- Minor code and linting fixing

- 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

- Added definition of algorithm in proto file
- Minor code comments and TODOs added

- Defined new dlt.proto file

- extended proto file to support retrieval of both services and connections, e.g., services requested + sub-services, and the connections and sub-connections supporting the services and sub-services.
- minor bug fixings in MockServicerImpl_Context and implementation of support for Slices
- implemented and pre-tested unitary tests for PathComp
- implemented in PathComp service the logic to retrieve context data, and the skeleton to retrieve the replies to compute requests.

- initial skeleton (not functional)