[api-extractor] fix references from computed properties

[sranka]

Summary

Fixes #3629

Details

The code that checks whether a node is in an expression context was incomplete, an expression also appears inside object's computed property.

How it was tested

Tested manually, against an example repository described in #3629 , the issue is solved with the changes in this PR.

[ghost]

All CLA requirements met.

[sranka]

@zelliott test case added, results manually reviewed

[zelliott]

@octogonz I think this is ready for you to take a look!