PostgreSQL array columns were serialized as JSON arrays (e.g. [1,2,3])
by serde_json::Value::Array Display, producing invalid SQL literals like
'[1,2,3]' and '[]' instead of PostgreSQL's required '{1,2,3}' and '{}'.
Add format_pg_array_sql_literal helper and apply it to all three SQL
literal formatting paths: escape_value_typed (transfer), format_export_sql_literal
(database_export), and format_grid_sql_literal (data_grid_sql).
t8y2