fix: blockstore operations should throw when passed an aborted signal

[achingbrain]

If an aborted AbortSignal is passed to blockstore operations, the operation should throw an AbortError.

Change checklist

• [x] I have performed a self-review of my own code
• [ ] I have made corresponding changes to the documentation if necessary (this includes comments as well)
• [x] I have added tests that prove my fix is effective or that my feature works