Move codeformat folder to tools (#35758)

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>

assets/misspellings.csv

@@ -0,0 +1,21 @@
+acounts,accounts
+canidate,candidate
+comfirm,confirm
+converage,coverage
+currrently,currently
+delimeter,delimiter
+differrent,different
+exclusing,excluding
+finshed,finished
+formated,formatted
+inderect,indirect
+insuficient,insufficient
+likly,likely
+mergable,mergeable
+overrided,overridden
+priortized,prioritized
+registeration,registration
+reuqest,request
+reviwer,reviewer
+superceded,superseded
+underlaying,underlying