Add functionality to navigate to start and end nodes of a connector.

[reddyashish]

Purpose

Task: https://jira.autodesk.com/browse/DYN-4836

Added the functionality to focus on the start/end nodes of the connector. These options are added to the connector context menu. I tried adding the input binding for '< 'and '>' as shortcut keys but had issues triggering them.
Will also add some tests.

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

Release Notes

Add functionality to navigate to start and end nodes of a connector.

Reviewers

@QilongTang @zeusongit

[QilongTang]

LGTM, please add tests if apply

[reddyashish]

Added the tests.

[reddyashish]

master-5 seems to be failing for most of the jobs.
Self-serve job on master-15 passed: https://master-15.jenkins.autodesk.com/view/DYN/job/DYN-DevCI_Self_Service/1097/