DDL for vector type

Implement DDL for Vector Type

Implement CREATE TAG for Vector Type

Thrift: Modify ColumnTypeDef

• Use type_lenght to indicate the dimension of the vector type.

struct ColumnTypeDef {
    1: required common.PropertyType    type,
    // type_length is valid for fixed_string type and vector type for dimension
    2: optional i16                    type_length = 0,
    // geo_shape is valid for geography type
    3: optional GeoShape               geo_shape,
}

Graphd: Create Tag Validator

We should distinguish the vector columns and other columns from parser.

Metad: Modify Processor

Add the solution to handle the vector columns from CreateTagReq.schema.