The manually tracked `resolved`-property is no longer necessary, since the same information is now directly available on all `PromiseCapability`-instances.
Furthermore, since the `PDFObjects.resolve` method is not documented as accepting e.g. only Object-data, we probably shouldn't resolve the `PromiseCapability` with the `data` and instead only store it on the `PDFObjects`-instance.[1]
---
[1] While Objects are passed by reference in JavaScript, other primitives such as e.g. strings are passed by value and the current implementation *could* thus lead to increased memory usage. Given how we're using `PDFObjects` in the PDF.js code-base none of this should be an issue, but it still cannot hurt to change this.