v2.0.2 fix problems after code review

- dropped Package-Version metadata.
- zero-input-full-width-mode renamed to zero-input-full-width-p.
- zero-input-toggle is now an obsolete alias for zero-input-mode.
- use `defvar-local' when variable is always buffer local.
- moved test data to debug/test files.
- fixed typo. zero-input-pinin-service > `zero-input-pinyin-service'.