We've had issues with forgetting to close readers and writers.
Add leak tracking to find those pesky issues.
Change-Id: If6b0ad6e9958318a7e0affee9c6d0a1ece412b6d
The blobstore implementation is entirely related to storagenode, so the
rightful place is together with the storagenode implementation.
Fixes https://github.com/storj/storj/issues/5754
Change-Id: Ie6637b0262cf37af6c3e558556c7604d9dc3613d