EC: Implement the EC Reconstruction coordinator

This Jira implemented the reconstruction coordinator logic.

ECReconstruction coordinator re-uses the ECReconstructedStripedInputStream, ECBlockOutputStream and ContainerProcolCalls for reconstruction of a container.

Steps are a follows:

For a container reconstruction task, the main flow is:
  - ListBlock from all healthy replicas
  - calculate effective block group len for all blocks
  - create RECOVERING containers in TargetDNs
  -  for each block
  -    build a ECReconstructedStripedInputStream to read healthy chunks
  -    build a ECBlockOutputStream to write out decoded chunks
  -      for each stripe
  -        use ECReconstructedStripedInputStream.recoverChunks to decode chunks
  -        use ECBlockOutputStream.write to write decoded chunks to TargetDNs
  -    PutBlock
  - Close RECOVERING containers in TargetDNs