Fix sqlancer#1209: UNARY_PLUS operator now converts values to DOUBLE PRECISION by guptapratykshh · Pull Request #1220 · sqlancer/sqlancer

This PR addresses an issue where the UNARY_PLUS operator (+) wasn't properly handling type promotion. In SQL (including Materialize/PostgreSQL), applying the unary + operator on a numeric value should promote it to DOUBLE PRECISION. The previous implementation simply returned the input value without performing any conversion, which could lead to mismatches in expected vs. actual results during testing.

Closes #1209