orm: add != (#9600)

vlib/orm/orm_test.v

@@ -32,6 +32,11 @@ fn test_orm_sqlite() {
 	db.exec("insert into User (name, age) values ('Peter', 31)")
 	db.exec("insert into User (name, age, is_customer) values ('Kate', 30, 1)")
 
+	c := sql db {
+		select count from User where id != 1
+	}
+	assert c == 2
+
 	nr_all_users := sql db {
 		select count from User
 	}

vlib/v/gen/c/sql.v

@@ -478,6 +478,7 @@ fn (mut g Gen) expr_to_sql(expr ast.Expr, typ SqlType) {
 			g.sql_side = .left
 			g.expr_to_sql(expr.left, typ)
 			match expr.op {
+				.ne { g.write(' != ') }
 				.eq { g.write(' = ') }
 				.gt { g.write(' > ') }
 				.lt { g.write(' < ') }