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)

models/migrations/v189.go

@@ -81,7 +81,7 @@ func unwrapLDAPSourceCfg(x *xorm.Engine) error {
 			}
 			err := jsonUnmarshalHandleDoubleEncode([]byte(source.Cfg), &wrapped)
 			if err != nil {
-				return fmt.Errorf("failed to unmarshal %s: %w", string(source.Cfg), err)
+				return fmt.Errorf("failed to unmarshal %s: %w", source.Cfg, err)
 			}
 			if wrapped.Source != nil && len(wrapped.Source) > 0 {
 				bs, err := json.Marshal(wrapped.Source)