--Configuration : Add ability to handle vectors of fields within subconfigs

[jturner65]

Motivation and Context

This PR takes the support for vectors of points introduced with MarkerSets, promotes it to the underlying Configuration and expands it to be vectors of any type. In a nutshell a vector of data can be stored in a subconfig by having the key be a string rep of the index in the vector referencing the value.

This obviates the need for local vectors to implementers of the Configuration class, such as SemanticAttributes, which stored the polyloop of points in a vector member varaiable.

How Has This Been Tested

Locally c++ and python tests pass.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have completed my CLA (see CONTRIBUTING)
• I have added tests to cover my changes.
• All new and existing tests passed.