Refactor CSRF protection modules, make sure CSRF tokens can be up-to-date. (#19337)

Do a refactoring to the CSRF related code, remove most unnecessary functions.
Parse the generated token's issue time, regenerate the token every a few minutes.

modules/context/auth.go

@@ -63,7 +63,7 @@ func Toggle(options *ToggleOptions) func(ctx *Context) {
 		}
 
 		if !options.SignOutRequired && !options.DisableCSRF && ctx.Req.Method == "POST" {
-			Validate(ctx, ctx.csrf)
+			ctx.csrf.Validate(ctx)
 			if ctx.Written() {
 				return
 			}