Draft: Resolve "task-runner backup-utility : parallel compression"

What does this MR do?

• Install the two documented alternative compression methods:
  • pigz
  • zstd
• Make sure that the backup-utility verifies the existence of COMPRESS_CMD and UNCOMPRESS_CMD and includes them in the tar command line.

This is an effort to a) make that feature available on Charts and b) make backup creation more consistent across platforms.

Related issues

Closes task-runner backup-utility : parallel compression (#1481 - closed)

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