Add more linters to improve code readability (#19989)

Add nakedret, unconvert, wastedassign, stylecheck and nolintlint linters to improve code readability

- nakedret - https://github.com/alexkohler/nakedret - nakedret is a Go static analysis tool to find naked returns in functions greater than a specified function length.
- unconvert - https://github.com/mdempsky/unconvert - Remove unnecessary type conversions
- wastedassign - https://github.com/sanposhiho/wastedassign -  wastedassign finds wasted assignment statements.
- notlintlint -  Reports ill-formed or insufficient nolint directives
- stylecheck - https://staticcheck.io/docs/checks/#ST - keep style consistent
  - excluded: [ST1003 - Poorly chosen identifier](https://staticcheck.io/docs/checks/#ST1003) and [ST1005 - Incorrectly formatted error string](https://staticcheck.io/docs/checks/#ST1005)

modules/setting/i18n.go

@@ -40,12 +40,12 @@ func defaultI18nLangs() (res []string) {
 	for i := 0; i < len(defaultI18nLangNames); i += 2 {
 		res = append(res, defaultI18nLangNames[i])
 	}
-	return
+	return res
 }
 
 func defaultI18nNames() (res []string) {
 	for i := 0; i < len(defaultI18nLangNames); i += 2 {
 		res = append(res, defaultI18nLangNames[i+1])
 	}
-	return
+	return res
 }