fix(mssql): map BIT to bool in compile-time type checking

The query! macros resolve a column's Rust type via
<Mssql as TypeChecking>::return_type_for_id, which only searches the type list
in impl_type_checking!. `bool` was missing from that list, so a BIT column had
no built-in mapping and failed to compile:

  error: no built-in mapping found for type BIT of column ("deleted")
  error[E0277]: the trait bound `(): sqlx::Decode<'_, Mssql>` is not satisfied

The runtime bool/BIT support already exists (types/bool.rs). Add `bool` to the
list, placed after the integer types: `bool::compatible` also matches
TINYINT/INT/SMALLINT/BIGINT, but the integer types (whose int_compatible does
NOT match BIT) claim those first, so only BIT falls through to bool. Fixes the
tests/mssql/macros.rs `test_query_simple` test.

Author: Pablo Carrera <pabloce@poscye.com>

Author: pabl-o-ce

sqlx-mssql/src/type_checking.rs

@@ -12,6 +12,12 @@ impl_type_checking!(
         i16,
         i32,
         i64,
+
+        // Must come after the integer types: `bool::compatible` also matches
+        // TINYINT/INT/SMALLINT/BIGINT, but the integer types claim those first;
+        // BIT is matched only by `bool`.
+        bool,
+
         f32,
         f64,