[Prototype only]: Add GC handle for incremental GC and remove tracking state in summarizer nodes

[agarwal-navin]

Description

This prototype introdues a "GC handle" similar to the summary handle. Nodes that did not change since last GC should return a "GC handle". The garbage collector will then get the GC data for that node and it's sub-tree from the previous GC data. This will remove all the GC data state tracking in summarizer node which is complex.

Reviewer guidance

This is meant as a prototype only and is not intended to be merged.

[microsoft-github-policy-service[bot]]

This PR has been automatically marked as stale because it has had no activity for 60 days. It will be closed if no further activity occurs within 8 days of this comment. Thank you for your contributions to Fluid Framework!

[microsoft-github-policy-service[bot]]

This PR has been automatically marked as stale because it has had no activity for 60 days. It will be closed if no further activity occurs within 8 days of this comment. Thank you for your contributions to Fluid Framework!