update syn to v2.0, large update

satrs-mib/codegen/tests/basic_with_info.rs

@@ -0,0 +1,8 @@
+//! Basic check which just verifies that everything compiles
+use satrs_core::res_code::ResultU16;
+use satrs_mib::resultcode;
+
+#[resultcode(info = "This is a test result where the first parameter is foo")]
+const _TEST_RESULT: ResultU16 = ResultU16::const_new(0, 1);
+
+fn main() {}