Fix entity codegen for PostgreSQL enum array columns

Array enum columns were emitted as scalar active-enum types because
get_column_rs_types_with_enum_idents used get_inner_col_type(), which
unwraps Array(Enum) to Enum. Route array columns through get_rs_type()
instead.

Fixes #3120

Co-authored-by: Cursor <cursoragent@cursor.com>