* Make EC detection context aware
* Update register.go
* Speed up EC detection planning
* Add tests for EC detection planner
* optimizations
detection.go: extracted ParseCollectionFilter (exported) and feed it into the detection loop so both detection and tracing share the same parsing/whitelisting logic; the detection loop now iterates on a sorted list of volume IDs, checks the context at every iteration, and only sets hasMore when there are still unprocessed groups after hitting maxResults, keeping runtime bounded while still scheduling planned tasks before returning the results.
erasure_coding_handler.go: dropped the duplicated inline filter parsing in emitErasureCodingDetectionDecisionTrace and now reuse erasurecodingtask.ParseCollectionFilter, and the summary suffix logic now only accounts for the hasMore case that can actually happen.
detection_test.go: updated the helper topology builder to use master_pb.VolumeInformationMessage (matching the current protobuf types) and tightened the cancellation/max-results tests so they reliably exercise the detection logic (cancel before calling Detection, and provide enough disks so one result is produced before the limit).
* use working directory
* fix compilation
* fix compilation
* rename
* go vet
* fix getenv
* address comments, fix error
Chris Lu