Firebirust v0.5.3 is released

Firebirust v0.5.3 is released with a few changes :

This release adds inspectable column metadata to statements, tightens and cleans up several internal APIs, expands tests

Highlights

• Add column inspection API on Statement and StatementAsync:
• column_count()
• column_names() -> Vec<&str>
• column_metadata(col: usize) -> Option<(sqltype, sqlscale, sqlsubtype, sqllen, null_ok, fieldname, relname, ownname)>
• Improved test coverage — sync and async tests now assert column count, names, and metadata.
• Internal refactor:
• SQL type constants promoted to crate root.
• Many protocol/constants now have crate-level visibility (pub(crate)).
• XSQLVar made crate-private (pub(crate)); parsing now uses utils:: helpers.