update tests and fix bugs in parser

[NTTVy03]

Update tests

1. Update parser tests
2. Add scope parsing tests
3. Refactor syntax test
4. Use snapshot testing

Fix

1. Remove trivial tokens before template name and function name...
2. Replace expect with eat in the block parser
3. Change param type in find signal methods (template)
4. Add error report in expect and expect_any

Add some other token kinds

1. Add combined tokens (+=, *=, >>=,...)
2. Re-priority tokens

[vuvoth]

quick review!

[vuvoth]

Why do you add the Serialize trait?

[NTTVy03]

we need that trait for the snapshot testing (insta)

fn test(source: &str, snapshot_name: &str) {
        let input = Input::new(&source);

        insta::assert_yaml_snapshot!(snapshot_name, input);
}