Implement toString method in InformationSchemaTableHandle and InformationSchemaColumnHandle

[ebyhr]

Description

This simplifies EXPLAIN result:

trino> explain table memory.information_schema.tables;
                                                                    Query Plan
--------------------------------------------------------------------------------------------------------------------------------------------------
 Trino version: testversion
 Fragment 0 [SOURCE]
     Output layout: [table_catalog, table_schema, table_name, table_type]
     Output partitioning: SINGLE []
     Output[columnNames = [table_catalog, table_schema, table_name, table_type]]
     │   Layout: [table_catalog:varchar, table_schema:varchar, table_name:varchar, table_type:varchar]
     │   Estimates: {rows: ? (?), cpu: 0, memory: 0B, network: 0B}
     └─ TableScan[table = memory:InformationSchemaTableHandle[catalogName=memory, table=TABLES, prefixes=[memory.*.*], limit=OptionalLong.empty]]
            Layout: [table_catalog:varchar, table_schema:varchar, table_name:varchar, table_type:varchar]
            Estimates: {rows: ? (?), cpu: ?, memory: 0B, network: 0B}
            table_type := InformationSchemaColumnHandle[columnName=table_type]
            table_catalog := InformationSchemaColumnHandle[columnName=table_catalog]
            table_schema := InformationSchemaColumnHandle[columnName=table_schema]
            table_name := InformationSchemaColumnHandle[columnName=table_name]

↓

                                                Query Plan
----------------------------------------------------------------------------------------------------------
 Trino version: testversion
 Fragment 0 [SOURCE]
     Output layout: [table_catalog, table_schema, table_name, table_type]
     Output partitioning: SINGLE []
     Output[columnNames = [table_catalog, table_schema, table_name, table_type]]
     │   Layout: [table_catalog:varchar, table_schema:varchar, table_name:varchar, table_type:varchar]
     │   Estimates: {rows: ? (?), cpu: 0, memory: 0B, network: 0B}
     └─ TableScan[table = memory:catalog=memory table=TABLES prefixes=[memory.*.*]]
            Layout: [table_catalog:varchar, table_schema:varchar, table_name:varchar, table_type:varchar]
            Estimates: {rows: ? (?), cpu: ?, memory: 0B, network: 0B}
            table_catalog := table_catalog
            table_schema := table_schema
            table_type := table_type
            table_name := table_name

Release notes

(x) This is not user-visible or is docs only, and no release notes are required.