feat: Add a ConnectorList attribute to enable the connection of an arbitrary number of dependent modules.

[Klafyvel]

Description

This PR introduces ConnectorList attributes to Qudi modules. I have updated the module manager machinery, as well as the taskrunner to be able to use those.

Motivation and Context

This is done in order to be able to have modules that don't know in advance how many connections of a certain interface they will have. A typical use case is to combine many switches together into a single switch hardware; you can see a running example here.

How Has This Been Tested?

I tested this modification locally, and made a minimal git repository that uses ConnectorList attributes for a hardware and for a task.

Types of changes

• Bug fix
• New feature
• Breaking change (Causes existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• I have documented my changes in /docs/changelog.md.
• My change requires additional/updated documentation.
• I have updated the documentation accordingly.
• I have added/updated the config example for any module docstrings as necessary.
• I have checked that the change does not contain obvious errors
  (syntax, indentation, mutable default values, etc.).
• I have tested my changes using 'Load all modules' on the default dummy configuration.
• All changed Jupyter notebooks have been stripped of their output cells.