### What changes were proposed in this pull request?
This PR enhances `Catalog.createTable()` to allow users to set the table's description. This corresponds to the following SQL syntax:
```sql
CREATE TABLE ...
COMMENT 'this is a fancy table';
```
### Why are the changes needed?
This brings the Scala/Python catalog APIs a bit closer to what's already possible via SQL.
### Does this PR introduce any user-facing change?
Yes, it adds a new parameter to `Catalog.createTable()`.
### How was this patch tested?
Existing unit tests:
```sh
./python/run-tests \
--python-executables python3.7 \
--testnames 'pyspark.sql.tests.test_catalog,pyspark.sql.tests.test_context'
```
```
$ ./build/sbt
testOnly org.apache.spark.sql.internal.CatalogSuite org.apache.spark.sql.CachedTableSuite org.apache.spark.sql.hive.MetastoreDataSourcesSuite org.apache.spark.sql.hive.execution.HiveDDLSuite
```
Closes#27908 from nchammas/SPARK-31000-table-description.
Authored-by: Nicholas Chammas <nicholas.chammas@liveramp.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
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