Remove name field from CNAB dependency representation in bundle.json

[carolynvs]

What does this change

The name field for a dependency is not in the spec because CNAB represents a dependency as a map entry, keyed by name. We use a name internally just to make things easier while working with dependency entries but they shouldn't be written out with a name field.

I have updated how we serialize the dependency structs so that even when name is populated, we don't write it to bundle.json

What issue does it fix

Fixes #2659

Notes for the reviewer

N/A

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