implement clickhouse metadata APIs

[onlyjackfrost]

(POST) /v2/ibis/clickhouse/metadata/tables

Request payload Example

{
  "connectionInfo": {
      "connectionUrl": "clickhouse://user:pwd@host:port/database?secure=1"
  }
}

or

{
  "connectionInfo": {
      "host": "localhost",
      "port":  8443,
      "user": "my-user",
      "password": "my-pwd",
      "database": "my-database"
  }
}

Response Example

• name: unique table name (might contain schema name, depends on are you listing table across schema or not )
• columns
  • name: column name in the datasource
  • type: column data type
  • notNull: boolean, nullable or not
  • description: column description(comment) if any
  • properties: column properties if any
• description: table description if any
• properties
  • schema: schema name to build tableReference
  • catalog: catalog name to build tableReference
  • table: table name to build tableReference
• primaryKey: the column name which is bind with primary constraint

[
    {
        "name": "dbo.REGION",
        "columns": [
            {
                "name": "R_COMMENT",
                "type": "VARCHAR",
                "notNull": false,
                "description": "",
                "properties": null
            }
        ],
        "description": "",
        "properties": {
            "schema": "db",
            "catalog": "def",
            "table": "REGION"
        },
        "primaryKey": ""
    },
]

(POST) /v2/ibis/clickhouse/metadata/constraints

Request payload Example

{
  "connectionInfo": {
      "connectionUrl": "clickhouse://user:pwd@host:port/database"
  }
}

Note: ClickHouse does not support foreign key constraints. This API will return an empty array for now.

Response Example

[]

[grieve54706]

How about adding a test for getting constraints that will return an empty array?

[grieve54706]

LGTM