fix(metadata-ingestion)glue connector failure when Optional field Type of PartitionKey is absent for a Table

[siladitya2]

Issue:
When the Optional field Type of PartintionKeys (PartitionKey["Type"]) is missing of a Table, the glue connector is failing with below exception.

  File "/datahub-ingestion/.local/lib/python3.10/site-packages/datahub/ingestion/source/aws/glue.py", line 1168, in get_schema_metadata
    hive_column_type=partition_key["Type"],
KeyError: 'Type'

Fix:
When the OptionalType field of Partitionkey is missing, we are mapping(avro schema mapping) the unknown Type with null Type for producing the MCE.

UI screenshot:

Additionally, adding a debug logger while extracting data from tables, which will help to debug any issue when connector failed to process data for a particular table.

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub