Add Timestamp converter, improve LongConverter for better SparkSQL support
Description
SparkSQL support limited set of time types: Timestamp and Date only. There is no Timestamp converter in the connector, surprisedly. I propose to add Timestamp converter and also improve LongConverter to convert all of the time classes to long representations, that will gives more convenient way to store time in SparkSQL tables
SparkSQL support limited set of time types: Timestamp and Date only. There is no Timestamp converter in the connector, surprisedly. I propose to add Timestamp converter and also improve LongConverter to convert all of the time classes to long representations, that will gives more convenient way to store time in SparkSQL tables