DYN-7946:PM - crash fix when removing custom nodes with identical names

[dnenov]

Purpose

Fixes a crash where, while creating a new Package, attempting to remove CustomNodeDefinitions from the current loaded list of files would result in unhandled "Sequence contains no matching element" error. This is happening because of the way we handle custom nodes with duplicate naming, constructing the Display Name using the [namespace].[node name] combination.

The PR addresses the underlying cause of the issue.

https://jira.autodesk.com/browse/DYN-7946

Declarations

Check these if you believe they are true

• The codebase 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.
• This PR modifies some build requirements and the readme is updated
• This PR contains no files larger than 50 MB

Release Notes

• fixed a crash where removing custom nodes with identical names would cause a null "Sequence contains no matching element" due to how we handle duplicate node names

Reviewers

@jnealb
@QilongTang

FYIs

[github-actions]

See the ticket for this pull request: https://jira.autodesk.com/browse/DYN-7946

[github-actions]

UI Smoke Tests

Test: success. 11 passed, 0 failed.
TestComplete Test Result
Workflow Run: UI Smoke Tests
Check: UI Smoke Tests

[QilongTang]

Reported regression real? DynamoCoreWpfTests.RecordedTests.TestReconnectionUndo

[QilongTang]

Re-running validation at https://master-5.jenkins.autodesk.com/job/Dynamo/job/DynamoSelfServe/job/pullRequestValidation/16879/

[QilongTang]

Self serve passed, merging