Add hive_metastore.thrift machinery needed for alterTable
Add hive_metastore.thrift machinery needed for alterTable

This commit adds the minimum machinery needed to be able to
call metastore.alterTable(alterTableRequest).  That minimum
machinery is:
o Adding int field writeId, number 19, at the end of struct Table.
o Adding structs AlterTableRequest and AlterTableResponse.
o Adding new method alter_table_req(alterTableRequest).

electrum/presto-hive-apache