Purpose

This PR is to fix the crash exception reported in the task: https://jira.autodesk.com/browse/DYN-2101

In short, when a new package is being loaded into Dynamo(while the graph is open in automatic mode), the VM is reinitialized and reloads all the libraries(including the core one's) into the VM. So when the node's are resolved, execution run's are triggered asynchronously. This causes a thread timing issue as the post execution run steps are called after the VM is reset and the DSExecutable object is lost during the execution run. To avoid this case, we have added a flag to check if the packages are being loaded and skip those initial run's as a final run is anyways triggered after the reloading of libraries is completed.

In order to make sure, we do not have any new regressions, we plan to merge this to master first before merging into the RC_2.4 branch.

For testing: we have a UI automation test that @mjkkirschner added https://github.com/DynamoDS/DynamoUIAutomation/pull/155

TODO:
We plan to re-evaluate this whole workflow in the future.
Task: https://jira.autodesk.com/browse/DYN-2120

Declarations

Check these if you believe they are true

• The code base is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning, and are documented in the API Changes document.

Reviewers

@mjkkirschner @aparajit-pratap @QilongTang