Multi-var monitoring for PyProcModels

[elvinhajizada]

Issue Number: #75

Objective of pull request: Enable multi-Var and multi-OutPort probing of multiple processes using single Monitor proc.

Pull request checklist

Your PR fulfills the following requirements:

• [x] Issue created that explains the change and why it's needed
• [x] Tests are part of the PR (for bug fixes / features)
• [x] Docs reviewed and added / updated if needed (for bug fixes / features)
• [x] PR conforms to Coding Conventions
• [x] PR applys BSD 3-clause or LGPL2.1+ Licenses to all code files
• [x] Lint (flakeheaven lint src/lava tests/) and (bandit -r src/lava/.) pass locally
• [x] Build tests (pytest) passes locally

Pull request type

Please check your PR type:

• [ ] Bugfix
• [x] Feature
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] Documentation changes
• [ ] Other (please describe):

What is the current behavior?

• One Monitor Process can only probe single Var or OutPort of another Process. Multi-Var or Multi-OutPort monitoring of multiple processes are not possible. Each time user needs to create a new Monitor process.

What is the new behavior?

• Now user need to a single Monitor process, which can be used to probe multiple Vars and/or OutPorts of several other processes.

Does this introduce a breaking change?

• [x] No

Supplemental information

To enable multi-var probing this PR introduce dynamic creation of Vars and Ports in processes. For this purpose it introduces a new attribute to Vars and Ports, called parent_list_name. This is just a string that points to the name of a LavaType in ProcModel, corresponding to the collection of dynamically generated Ports or Vars of a specific type (e.g. RefPort, InPort, etc.). Practically, all of the members of a process that has the same parent_list_name attribute will use the same LavaType in its ProcModel with the name parent_list_name. This solves the problem of correspondence between Process members and ProcModel members in the case of dynamical creation new Ports or Vars