feat: impl alter table in distributed mode (#572)

src/api/src/lib.rs

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-mod column_def;
 pub mod error;
 pub mod helper;
 pub mod prometheus;

src/api/src/v1.rs

@@ -21,4 +21,5 @@ pub mod codec {
     tonic::include_proto!("greptime.v1.codec");
 }
 
+mod column_def;
 pub mod meta;