A SQL Database object abstraction class

Changes for v1.0.0 - 2023-12-13T12:53:38Z

• Corrected the use of _is_hash for a stricter and narrower meaning.
• Corrected error in _where_having in DB:😮bject::Query
• Corrected method structure() in DB:😮bject:😛ostgres::Tables to take under account arrays.
• Updated method 'distinct' in DB:😮bject:😛ostgres to allow for multiple arguments.
• Improved the method structure() in DB:😮bject:Tables, DB:😮bject😛ostgres::Tables, DB:😮bject:SQLite::Tables and DB:😮bject:Mysql::Tables
• Updated DB:😮bject::Fields and DB:😮bject::Field, extending the later
• Implemented a table object caching mechanism, which is disabled by default