Corrects typo: messager to messenger

[pjleonard37]

What does this pull request do?

This PR fixes a type "messager" should be "messenger" across the whole codebase.

What is the motivation and context behind this change?

Pull request checklist:

• [ ] Add a changelog entry.
• [ ] Write tests for all new functionality. If tests were not written, please explain why.
• [ ] Add documentation comments for any added or updated public APIs.