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/markup/markdown/markdown.go

@@ -156,7 +156,7 @@ func actualRender(ctx *markup.RenderContext, input io.Reader, output io.Writer)
 
 		log.Warn("Unable to render markdown due to panic in goldmark: %v", err)
 		if log.IsDebug() {
-			log.Debug("Panic in markdown: %v\n%s", err, string(log.Stack(2)))
+			log.Debug("Panic in markdown: %v\n%s", err, log.Stack(2))
 		}
 	}()
 
@@ -185,7 +185,7 @@ func render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error
 
 		log.Warn("Unable to render markdown due to panic in goldmark - will return raw bytes")
 		if log.IsDebug() {
-			log.Debug("Panic in markdown: %v\n%s", err, string(log.Stack(2)))
+			log.Debug("Panic in markdown: %v\n%s", err, log.Stack(2))
 		}
 		_, err = io.Copy(output, input)
 		if err != nil {