Support setting table and column comments in Delta Lake

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Description

Delta Logs corresponding to comment on table and column statements via spark-sql:

COMMENT ON TABLE testdelta IS 'this is my delta table';

ALTER TABLE testdelta ALTER COLUMN a COMMENT 'this is my a column';

[root@hadoop-master /]# hdfs dfs -cat /user/hive/warehouse/testdelta/_delta_log/00000000000000000001.json
{"metaData":{"id":"e4e5196b-311c-4883-9e93-b97b7711f1a1","description":"this is my delta table","format":{"provider":"parquet","options":{}},"schemaString":"{\"type\":\"struct\",\"fields\":[{\"name\":\"a\",\"type\":\"integer\",\"nullable\":true,\"metadata\":{}},{\"name\":\"b\",\"type\":\"integer\",\"nullable\":true,\"metadata\":{}}]}","partitionColumns":[],"configuration":{},"createdTime":1656043296180}}
{"commitInfo":{"timestamp":1656043342692,"operation":"SET TBLPROPERTIES","operationParameters":{"properties":"{\"comment\":\"this is my delta table\"}"},"readVersion":0,"isolationLevel":"Serializable","isBlindAppend":true,"operationMetrics":{},"engineInfo":"Apache-Spark/3.2.1 Delta-Lake/1.2.1","txnId":"2ae38bea-9f58-4628-be9e-b4a36fee8e96"}}
[root@hadoop-master /]# hdfs dfs -cat /user/hive/warehouse/testdelta/_delta_log/00000000000000000002.json
{"metaData":{"id":"e4e5196b-311c-4883-9e93-b97b7711f1a1","description":"this is my delta table","format":{"provider":"parquet","options":{}},"schemaString":"{\"type\":\"struct\",\"fields\":[{\"name\":\"a\",\"type\":\"integer\",\"nullable\":true,\"metadata\":{\"comment\":\"this is my a column\"}},{\"name\":\"b\",\"type\":\"integer\",\"nullable\":true,\"metadata\":{}}]}","partitionColumns":[],"configuration":{},"createdTime":1656043296180}}
{"commitInfo":{"timestamp":1656043505250,"operation":"CHANGE COLUMN","operationParameters":{"column":"{\"name\":\"a\",\"type\":\"integer\",\"nullable\":true,\"metadata\":{\"comment\":\"this is my a column\"}}"},"readVersion":1,"isolationLevel":"Serializable","isBlindAppend":true,"operationMetrics":{},"engineInfo":"Apache-Spark/3.2.1 Delta-Lake/1.2.1","txnId":"6fe8a96b-8ca6-450f-a26a-a08506db9a57"}}

Is this change a fix, improvement, new feature, refactoring, or other?

New feature.

Is this a change to the core query engine, a connector, client library, or the SPI interfaces? (be specific)

Delta Lake connector.

How would you describe this change to a non-technical end user or system administrator?

Add the ability to perform statements like

COMMENT ON TABLE deltatable IS 'My table description';
COMMENT ON COLUMN deltatable.deltacolumn IS 'My column description';

Related issues, pull requests, and links

Documentation

(x) No documentation is needed.
( ) Sufficient documentation is included in this PR.
( ) Documentation PR is available with #prnumber.
( ) Documentation issue #issuenumber is filed, and can be handled later.

Release notes

( ) No release notes entries required.
(x) Release notes entries required with the following suggested text:

# Delta Lake
* Add support for `COMMENT` statement on table and column