Followup to https://github.com/go-gitea/gitea/pull/35734.
- Move `codeformat` folder to `tools`
- Add `tools` to `GO_DIRS`
- Move `misspellings.csv` to `assets` so we can lint the whole `tools`
directory without filter shenanigans.
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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
