Proper extraction of projection column for metadata projection.

[20001020ycx]

Issue #122 discusses the current problem of extracting projection column

Your Environment

• Presto version used:
• Storage (HDFS/S3/GCS..):
• Data source and connector used:
• Deployment (Cloud or On-prem):
• Pastebin link to the complete debug logs:

Expected Behavior

Current Behavior

Possible Solution

Steps to Reproduce

Screenshots (if appropriate)

Context