Print sdk artifact sizes

[adwsingh]

Issue #, if available:

Description of changes:

========== Compiled Artifact Size Statistics ==========
  SDKs processed: 423
  Average size:   3.1 MB (3,206,501 bytes)
  Min size:       109.3 KB (111,964 bytes) -> marketplace-reporting
  Max size:       49.7 MB (52,129,916 bytes) -> ec2
  Total:          1293.5 MB (1,356,350,099 bytes)
=======================================================

Top 5 largest SDKs:
  ec2                                                49.7 MB
  sagemaker                                          32.4 MB
  quicksight                                         29.2 MB
  connect                                            25.3 MB
  glue                                               18.6 MB

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