map data type limitations

[gaoboal]

Bug Description
test table: CREATE TABLE t1 (c1 string, c2 int, c3 MAP<string, string>);

1. In the desc t1; statement, the key and value types of the map are not displayed.
2. In the SHOW CREATE TABLE t1; statement, columns of type map are not displayed.
3. In the SQL syntax documentation for table creation, the support for the map type is not specified. It is necessary to add support documentation for the map type and provide an example. https://openmldb.ai/docs/zh/main/openmldb_sql/ddl/CREATE_TABLE_STATEMENT.html
4. After executing the statement INSERT INTO t1 VALUES ("1", 1, map(1, "12", 2, "100"));, a warning-level alert log is being displayed.
   insert into t1 values ("1", 1, map(1, "12", 2, "100"));
W20240429 14:40:09.353835 19961 codec.cc:82] type is not supported
5. In the SELECT * FROM t1; statement, the columns are displaying incorrectly or out of alignment.
   

[aceforeverd]

Thanks

1. In the desc t1; statement, the key and value types of the map are not displayed.
2. In the SHOW CREATE TABLE t1; statement, columns of type map are not displayed.

• desc or show create table do not handle map type

3. In the SQL syntax documentation for table creation, the support for the map type is not specified. It is necessary to add support documentation for the map type and provide an example. https://openmldb.ai/docs/zh/main/openmldb_sql/ddl/CREATE_TABLE_STATEMENT.html

fixed by #3912

4. After executing the statement INSERT INTO t1 VALUES ("1", 1, map(1, "12", 2, "100"));, a warning-level alert log is being displayed.
   insert into t1 values ("1", 1, map(1, "12", 2, "100"));
W20240429 14:40:09.353835 19961 codec.cc:82] type is not supported

• enhancement, not affect correctness

5. In the SELECT * FROM t1; statement, the columns are displaying incorrectly or out of alignment.
   

• known issue, docs updated in docs: add map desc in create table #3912 . e2e query support requires more fix like deprecating legacy schema codec  #3722 , won't come very soon